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WHWB WEBINAR: ASSESSING HEAT STRESS — Transcript

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0:00Morning
0:06everyone. Good afternoon and good
0:08evening. Um, thanks for joining us today
0:10and welcome to Workplace Health Without
0:12Borders. My name is Lisa Solan and I'm
0:14vice president of WHWB and I'm also an
0:17assistant professor at the Dalana School
0:19of Public Health at the University of
0:21Toronto. Um, as you're joining, please
0:23introduce yourself in the chat. Um, also
0:26tell us where you're from. um and maybe
0:29um maybe your current temperature if you
0:31know it. But um this session is being
0:34recorded
0:35um and we will get started as people are
0:38joining. I'd like to introduce our
0:40speaker today. Uh it's Dr. Ross
0:42Dorletto. Dr. D. Corletto is an
0:46occupational health and hygiene
0:48specialist with more than 40 years of
0:50experience across mining, refining and
0:53power industry in Australia and
0:55internationally. With a PhD in
0:57occupational health and a research
0:59masters in heat stress, he has made
1:01sustained contributions to understanding
1:03and managing thermal environments.
1:06[snorts] His publications include
1:08professional guidance textbooks, chap
1:10textbook chapters and international work
1:12on heat exposure and climate change. He
1:15has also helped develop heat stress
1:16assessment applications and university
1:18courses. Ross is a fellow past president
1:21and current president elect of the
1:24Australian Institute of Occupational
1:26Hygienists. He is an adjunct associate
1:29professor with the University of
1:30Queensland and Edith Cowan University.
1:35Ross is the director and principal
1:37consultant at Monitor Consulting
1:39Services in Brisbane, Australia, and he
1:42joins us in his this evening. This
1:45presentation is titled managing uh heat,
1:47old concepts and new ideas. Um and it
1:50will be followed by a Q&A uh question
1:53and answer period. However, you're
1:54invited to uh to to pose questions in
1:59the chat. Thank you. And it's my
2:01pleasure to hand it off to Ross, Dr.
2:04Dorletto. Thanks.
2:06>> Thanks for that introduction Lisa and
2:08welcome everyone and thanks for for
2:10joining us here. So the session today
2:14will be
2:16focusing more on the occupational
2:19uh hygiene side of heat stress. So what
2:22I'm looking at more is the actual
2:23assessment of um uh the the work
2:27environment and controlling the work
2:28environment. We'll touch on some of the
2:30other concepts. Um I won't spend a lot
2:33of time on areas such as um uh the
2:38actual acute illnesses, the heat strokes
2:40and the exhaustions and that because
2:42I've got a feeling that most of you on
2:44this this um presentation will already
2:46have a good knowledge of that. So we'll
2:48delve a little bit deeper and look at
2:50some other areas. So in the conversation
2:54we'll be having we'll look at very
2:57briefly at the u the changing climate
2:59and it's the impact it's having on the
3:02the work environment a little bit about
3:05illnesses uh acute and chronic. Chronic
3:07is an area that tends to get neglected.
3:09We we focus a lot on um on the acute
3:13side of things but chronic is now
3:15becoming quite an important aspect.
3:19uh the impact of heat on productivity uh
3:22which can be a very important area to
3:25look at particularly if you're trying to
3:26build a business case for resources.
3:31uh we'll also go into looking at some
3:33practical assessment of the work
3:35environment using uh what is the uh we
3:39call the the three-level protocols and
3:41I'll use some scenarios there
3:44uh and that'll give you an idea of how
3:46you can use these different tools.
3:48[snorts]
3:49So we'll be looking at the basic thermal
3:51risk assessment that's the first level
3:54um and heat strain tables. So, these are
3:57qualitative assessments and they're
4:00designed for the frontline worker.
4:02They're they're meant to be
4:03non-technical and easy to use for the
4:07more um significant exposures. We'll
4:10then go into looking at using rational
4:12indices. And this is more for the
4:15occupational health professional. And
4:17I'll show you how to use these indices
4:19to do a more quantitative assessment of
4:23a work environment and how to get a
4:25better understanding of what potential
4:27controls
4:28uh look like. And then finally, we'll
4:31touch on physiological monitoring. This
4:33really is becoming a growing area in uh
4:36in the management of heat stress. And
4:39we'll we'll look at some of the the
4:40benefits and also some of the
4:42disadvantages there.
4:45So the bottom line to this one is all
4:47about utilizing the hierarchy of
4:50controls effectively. One of the things
4:52I tend to find is often with heat stress
4:55control we tend to focus a bit too much
4:58on administrative controls. So through
5:01that throughout this presentation I'll
5:02try and point you in the direction of
5:05utilizing that hierarchy and starting at
5:07the top. We'll also finish off with some
5:11of the resources that are available that
5:12you can go into and look at. So to kick
5:16off our changing climate, now whether
5:19you're a climate skeptic or whether
5:21you're um believe in the the climate
5:24change pro uh phenomenon, what we do
5:28know is that temperatures are getting
5:31hotter. Whether it's a natural cycle or
5:32something caused by uh the uh human
5:37occupation of the planet, we are seeing
5:39changes in the climate and things are
5:41getting hotter.
5:43In January 2016, the um World
5:46Meteorological Organization confirmed
5:49that the average global temperature had
5:52already reached one degree. The change
5:55had already increased by one degree.
5:58And under current policies, they they
6:00project this is going to rise to 2.7°
6:03above pre-industrial levels.
6:06Now, normally you would say, well, 2.7°
6:091°ree here there, it's not going to make
6:11a big difference in a hot work
6:13environment.
6:14But this is an average. And the thing we
6:16have to be aware of is that we are with
6:20that increasing average, we are starting
6:23to see an increase of extreme heat
6:26events. And for example, here in in West
6:29Africa, there's been a doubling of very
6:31hot days since 1960. So these extreme
6:34events can have a very significant
6:36impact
6:38on uh areas such as the work environment
6:41in agriculture,
6:43in construction, and in manufacturing.
6:46And don't forget service sectors, things
6:48like tourism, transport, and sport. They
6:51are also impacted by the these uh
6:53increasing um temperatures. And we saw
6:56this year in Europe the impact of some
6:59of these extreme events that they're
7:01just not used to.
7:04So obviously across the globe we have a
7:06number of climatic zones and depending
7:08on where you sit will depend on how you
7:11approach the assessment and the tools
7:13that you're using and we'll go into that
7:15in this presentation. So obviously from
7:18here I'm down here right down the bottom
7:20in uh and I sit up in this semi-ropical
7:24region up in the corner here of
7:26Australia and u you can see we have all
7:28three zones here and across the world
7:32also in the uh the other continents
7:33you'll see often the um the subtropical
7:37the tropicals and the temperate zones
7:40right so let's look at managing the
7:43issue and but one of the things I always
7:45like to start off with is some
7:46definitions.
7:48So when we talk about heat stress, heat
7:51stress is actually the impact of the
7:54environment. So the heat, the humidity,
7:57the metabolic workload, which is a key
7:59factor and the clothing. Now either
8:02individually or combined, these create
8:05the heat stress on the worker, right? So
8:08they create the heat stress on the
8:09worker.
8:12Heat strain is how the body responds to
8:14those stresses. So the way the body
8:16sweats, the increased heart rate, the
8:19increase in elevated core temperature
8:21and sometimes people use these terms
8:23interchangeably which is incorrect. So
8:26heat stress
8:28actually is the cause of heat strain on
8:30the body. And another term that
8:33sometimes gets a little bit confused
8:35are heat illnesses. You'll hear the term
8:38classical heat illnesses. Now these
8:41usually occur amongst those that are
8:43susceptible such as the elderly or the
8:46very young or those are not able to care
8:48for themselves. And often in the media
8:50when they talk about a heat wave and the
8:53impact on the the elderly and the young
8:56that we're talking more about classical
8:58heat illnesses. In our sort of area, we
9:01talk more along the exertional heat
9:04illnesses and this is associated with
9:07physical exercise or work resulting in
9:10that increase in metabolic load that can
9:13increase heat production and um along
9:16with the the environment itself can
9:19cause quite a load on the body. So there
9:21are some terms just to keep in mind
9:25when I do presentations. Often
9:28I like the interactive um sessions and
9:31I'll ask the group you know what is heat
9:34stress what what to you signals heat
9:37stress and the usual thing you'll get is
9:39oh uh you know heat exhaustion people
9:42collapsing
9:43um and those sorts of terms and which
9:45yeah true they are uh the ultimate signs
9:49of of the impact of heat stress on the
9:51body but the initial symptoms start very
9:54very early in the piece and these These
9:56are things like fatigue and lethargy.
9:58And you know on those very hot and humid
10:02days how it impacts and you feel that
10:04lethargy and that that disincclination
10:07to to do anything too strenuous. If we
10:10do nothing about it at this point, then
10:12it'll progress and it starts to impact
10:14on our performance and we start to see
10:17lowering in productivity,
10:20particularly in the workforce. And then
10:21we're starting to see uh a bigger
10:23impact. If we still do nothing about it,
10:26then this is when we start to see an
10:28increased rate of mistakes and
10:30accidents. And there are a lot of
10:31studies in the literature that will show
10:33you that in the as we get into the
10:36hotter climates and the hotter weather,
10:38we'll start to see an increase in safety
10:41incidents and mistakes and poor
10:43decisions. It takes just that little bit
10:45longer for the guys to get their spanner
10:47on the on that the nut or or the
10:50screwdriver on the end of the screw or
10:52things slip off and you get a lot of um
10:55uh hand injuries and the like. So we do
11:00see that other impact and then finally
11:02if we don't do anything about these ones
11:04we that's when we end up with this
11:07increased uh risk of heat disorders. We
11:10start to see the dehydrations
11:12uh the heat exhaustions and ultimately
11:15if we don't do anything about it the
11:17potential fatalities with heat stroke.
11:19So the idea is to try and capture this
11:22in the early stages. So when we put in
11:24place our control plans, we don't wait
11:27until we see the s the symptoms of the
11:30heat disorder. We want to pick it up in
11:32the early stages, the fatigue and the
11:34lethargy so it doesn't progress up to
11:36that top level.
11:39Now acute illnesses I mentioned um I'm
11:42not going to spend a lot of time on this
11:44slide um because I figure most of you
11:46will be familiar with acute illnesses.
11:49uh they're pretty much done to death in
11:50our studies and when we're at university
11:53and we've got a I would assume most of
11:54you have got a very good understanding
11:57and this is the things such as prickly
11:59heat and heat rashes heat cramps fatigue
12:03or sometimes known as heat synopy or
12:05heat exhaustion and ultimately heat
12:08stroke which is either classical or
12:10exertional heat stroke. So these are the
12:12the more well-known illnesses or the
12:15acute illnesses that we see. What we
12:18tend not to talk about though
12:21are the chronic illnesses and uh Duke's
12:25DOS categorized these into three
12:27categories many years ago back in the
12:2980s. So type one consisted of the the
12:32after effects of an acute illness. So
12:34someone that had a heat stroke or an an
12:37acute heat exhaustion would suffer from
12:39a chronic effect afterwards. Type two
12:43were brought about by working in
12:44excessive jobs for a few weeks or a few
12:47months and these were becoming more more
12:49prominent. And finally there were those
12:51type what we called the type 3s which
12:54tended to to occur mainly among people
12:57living in climatically hot regions of
12:59the world. there are more uh and these
13:02are more prominent in those sorts of
13:04areas. Now, we're starting to see a lot
13:06more of the chronic illnesses than we
13:09used to. Whether it's because we're more
13:11aware of it and we're looking for it,
13:13I'm not sure, but they are starting to
13:15become more and more apparent.
13:17One of the big ones that comes up is
13:19chronic kidney disease.
13:21We're starting to see a high incidence
13:23of uric acid stones present in workers.
13:26This is a study done in 1993 on the
13:29glass factory. Uh similar study was done
13:32in the steel industry. Uh and we
13:34starting to see those stones appearing.
13:37So kidney stones and the like.
13:40Uh another one that is becoming more
13:42prominent is the messamerican nethropy.
13:45Uh this is was an epidemic of chronic
13:48kidney disease in hot coastal
13:50communities of Central America. And
13:52initially the the study focused on the
13:56use what they they thought was as a
13:59result of a a metabolic uh breakdown of
14:03cane sugar not cane sugars corn syrups
14:06uh because a lot of the workers were
14:08drinking um sodas or soft drinks and
14:11they thought there was this um along
14:14with the dehydration and the um
14:18[clears throat] metabolite from these
14:19sugars that they were causing this um uh
14:23sudden increase in kidney disease. But
14:26what was also found later on was this
14:28disease was also appearing amongst uh
14:31other uh workers in other areas and
14:34subtropical regions in Asia, Sri Lanka,
14:37Bangladesh, India, Africa and Egypt. So
14:39it wasn't just that condition. So this
14:42uh increase in kidney disease is
14:44becoming more and more apparent and
14:45we're starting to see it more in the in
14:48the workforce and they're appearing in
14:50uh in hospital admissions.
14:54I mentioned in one of the early slides
14:56we talked about decreased performance
14:58and low lower productivity as one of the
15:01the impacts particularly in the impact
15:04on cognitive function as well. Now when
15:07we come to producing a business case
15:10often then whether it be in a workplace
15:12or for research one of the things that
15:15uh we sometimes don't do very well as
15:16hygienists is is sell our case but when
15:20you start talking about loss in
15:22productivity and performance and uh this
15:26equates to a loss in dollars then we
15:28start to get a bit more attention. So
15:30it's not just about the health, it's
15:31also about u an e economic impact and we
15:35we there is definite evidence out there
15:38that the increase in u the increase in
15:42temperatures and the heat stress is
15:44starting to impact significantly in this
15:46area. So there was some study done by
15:49Calra Metal in uh 214 and they were
15:53estimating that the impact in 2030 due
15:56to workplace heat and reducing work was
16:00going to be estimated as around $2.4
16:02trillion. So we're talking some pretty
16:05massive amounts there.
16:08In a meta analysis done by Sahu and his
16:12cohort group um it was found that 30% of
16:15individuals working in heat stress
16:17conditions had losses in productivity
16:20and you can see from this graph as that
16:22the WBGT temperature increases we see
16:25that quite a significant uh decrease in
16:28productivity
16:30and florist
16:32uh did some similar work and also found
16:35that uh losses increased by 2.6% 6% for
16:38every degree increase above 24° C WBGT.
16:44So you can see there is quite a
16:46significant impact on productivity when
16:49we start to look at the heat stress. So
16:51it's not purely a health issue.
16:54Obviously it's an import health is our
16:56key uh target area but it also impacts
17:00in the the uh productivity side of
17:02things.
17:04So we know it's going to have a big
17:06impact on uh on the health of
17:08individuals and on the productivity and
17:11general businesses.
17:14The thing with heat stress though is
17:16that when we come to doing the
17:18assessment there is really no once one
17:21approach that fits all conditions. And
17:23that's where we sometimes get caught up.
17:26We try to find one model or one tool
17:29that we use right across the board. And
17:31unfortunately it doesn't work that way.
17:33Heat stress it says here assessment one
17:36size doesn't fit all. But having said
17:40that it doesn't mean that heat stress
17:41assessment has to be complicated. And
17:43there are some some models out there
17:45that are quite simple to use and we can
17:47use them early in the piece.
17:51So when we come to looking at the
17:53assessment there are a few things we
17:55need to consider.
17:57There are three really key areas of
18:00variation in the assessment of heat
18:02stress and I need to stress this one.
18:06Obviously environmental conditions,
18:07temperature, humidity, you know, air
18:10velocity, those sorts of things are
18:12going to impact on the um the heat
18:15stress applied on the individual.
18:18But then you have to look at the task
18:20being undertaken. As I mentioned
18:22earlier, metabolic heat production plays
18:24a key role in how our body generates and
18:28dissipates heat. So we need to look at
18:30the task being undertaken and include
18:32that in the assessment. And finally,
18:35personal factors. Not everybody is the
18:38same. So uh our workforce is can be made
18:42up of young fit individuals and some not
18:45so fit individuals. we shall we say and
18:48then there are health impacts and health
18:50conditions that can impact and
18:51medications and we'll look at these a
18:53bit further on. So you need to
18:55understand that within the work
18:57environment when assessing heat stress
18:59there are three key components that we
19:01need to to look at.
19:04So all three of these areas can impact
19:07or they interact with the scenario and
19:09they must all be considered in the
19:10assessment.
19:13Now I'll approach this looking using a
19:16model. This is a basically my preferred
19:19model. It's what we call the three-step
19:20protocol. It's a model that's been used
19:23at the in the AH for oh close to u close
19:27to 20 odd years now. And it's quite a
19:30simple model and easy to use.
19:33So the first level is what we call a
19:36basic qualitative heat risk assessment.
19:39So, this is targeted more or less at the
19:42shop floor or the um the supervisor.
19:44It's not complicated. The methodology
19:47here that's used, whichever one you
19:49choose, and we'll go through a couple of
19:51different examples, needs to be simple.
19:54It needs to be readily used by someone
19:57who doesn't have a technical background
19:59and [clears throat] uh doesn't
20:01necessarily have technical instruments
20:03available. So,
20:06I've seen different models used. Some
20:08people like to use a simple index such
20:10as the WBGT or effective temperature.
20:13Apparent temperature is a popular one
20:15these days. Uh, and it depends on what
20:17you want to use. There's questionnaires
20:19that are used and I'll show you some
20:21examples of that. But the bottom line is
20:23it has to be simple. So, this is your
20:25first level. Get in there, have a look,
20:28see what you can find and try and fix it
20:30quickly. [snorts] If you find that in
20:32that assessment that there is something
20:35that more significant of a risk, we then
20:38go to the level two and this is where
20:40the the occupational health and safety
20:42professional steps in. So we then go out
20:45and we start to collect data and we use
20:48what we would call a second level index.
20:51Now these indices are based on the heat
20:54balance equation. So they look at a
20:57quite a wide parameter of impacts and in
21:01the past they were very difficult to
21:03use. They're very complex. They use a
21:06number of algorithms.
21:08Um so they were tended to be pushed to
21:10one side. These days with the um the use
21:14of uh uh laptop computers, our access to
21:19websites and even phone apps, we can now
21:23do use a lot of these tools quite simply
21:25and readily. And we'll we'll look at how
21:28we can use those to not just look at
21:31what the exposure is, but also to look
21:33at how to implement the best forms of
21:35controls.
21:38And finally, physiological monitoring.
21:40And as I mentioned, this is a growing
21:42area. Uh we're starting to see a lot of
21:44wearable um monitors coming into the
21:48market. So, we're going to touch on
21:49this. This is particularly important
21:51where you've got scenarios which are of
21:55um high impact where this exposure time
21:58or the estimated exposure time would be
22:00less than 30 minutes or where people are
22:03wearing high levels of PPE such as
22:05hazmat suits uh and that sort of thing
22:08where the the um the their climate uh
22:13their microclimate is different to what
22:15is being experienced uh in the normal
22:17environment. and I'll go through each
22:19one of these three areas.
22:22So, let's look at the basic assessment
22:24first.
22:28Get rid [clears throat] of that. Right.
22:29So, the basic assessment needs to be
22:31prompt and a timely review of the
22:33thermal environment without requiring
22:36specialist input. So, we really want to
22:38engage the frontline workers and the
22:40supervisors in this. We want them to get
22:43in there and understand
22:45um so that you get that impact straight
22:49away.
22:51The method needs to provide enough
22:53information to support a technically
22:55valid argument which is important. You
22:58can use walkthrough surveys. You know,
23:00as a hygienist, we tend to like our walk
23:02through. Um I prefer to be out there and
23:05looking at the work environment wherever
23:07possible. I've got a my own little
23:10personal soap box where I say, you know,
23:12hygienists do not work out of offices.
23:14They're out in the field and that's what
23:16we need to do. And this is where your
23:18walk through survey can help. It can be
23:21used as a training tool and I'll show
23:23you as we go through also for HSSE
23:25interactions. HSSE interactions have
23:28become a big thing in the h obviously in
23:29the health and safety field where we
23:31start to get managers and supervisors
23:33and people getting out there and talking
23:35to our workers and frontline people. Uh
23:38but one of their issues is they never
23:40know what questions to ask in health.
23:41You they always we know what to ask them
23:43in safety and you know what sort of
23:45questions but health is complicated.
23:47Well, this is where we can start to use
23:49some of our questions u in these simple
23:52interactions.
23:54uh websites now can provide weather
23:57information and you know even things u
24:00they're very readily and there's apps
24:02out there that can give you that
24:03localized information that we can use
24:06and of course we've got modern
24:07instruments that are readily available
24:10the good old sling cychrometer which is
24:12one of my favorites I still use a sling
24:14cychrometer despite the fact that there
24:16are a lot more technical tools out there
24:18uh this is uh doesn't use any batteries
24:21it's intrinsically safe it's easy to
24:24carry carry around. So, that's one of my
24:27favorite tools. But, of course, there's
24:29also the the um the more technical tools
24:32that can data log and it can be quite
24:34useful as well.
24:36So, the work walkthrough survey this is
24:38the uh the bread and butter of the the
24:40hygienist. Um so, when we go through we
24:44need to look at certain things. We look
24:46at the area and operation
24:48characteristics. What sort of air flow
24:50do we have? What are the heat sources?
24:52Are they using fans? And this is where I
24:55think understanding your heat balance
24:58equation uh can be very very helpful.
25:01From that equation, it tells us where
25:03heat is gained and lost. And they're the
25:05sorts of things that we'll look at.
25:08Looking at engineering controls, if
25:10present, are they functioning properly?
25:12Check the maintenance records. I've been
25:14to sites where they've got very
25:17extensive chiller units that uh have
25:20never been had any maintenance done on
25:22them and virtually all they're doing is
25:24put is pushing around hot air. So if
25:28they've got the engineering controls,
25:31make sure that they are working as
25:32designed and there's a maintenance
25:34program that goes with them. And also
25:37verify all the information you've got
25:39from records. And this is where for me
25:41it's critical that you get out there
25:42into the workplace. It's all well and
25:44good to to read um data collected by
25:48someone else or or um information
25:52provided to you, but if you get out
25:54there and have a look at the workplace
25:56and talk with the opera the operators
25:59and the the management and get a really
26:01good feel for that work environment.
26:04And we talked about some of the the
26:06basic tools and this is one of them.
26:07This is called the the basic thermal
26:10risk assessment and uh it was designed
26:14uh for the frontline worker and the
26:16history behind this was uh I'm sure most
26:19of you as hygienists will have come
26:21across a situation where a worker walks
26:24into your office waving a thermometer
26:26and saying now at what temperature do we
26:28stop work
26:30and you know it's not that simple and to
26:32explain that to the the frontline
26:34workers we developed this this little
26:36tool which was just a a checklist that
26:39they would use and they would walk out
26:41there with this and this is a hard copy
26:42in the early days and for example they'd
26:45say well sun exposure is it indoors full
26:48shade part shade or no shade you know
26:50what hot surfaces are there and they
26:52would just tick off and from there we
26:56would determine what the metabolic work
26:58rate was which was there was a little
27:00table that was used that gave them a an
27:03estimate and then the apparent
27:05temperature we chose the apparent
27:06temperature because it was simple to
27:08calculate and that's just temperature
27:09and humidity from a chart. Uh the only
27:12reason we put the numbers in is as
27:15you're probably aware uh we're dealing
27:17often with technical people with
27:19engineers and with hygieneists and they
27:21like numbers. So we put the numbers in
27:23to help them get that feel for
27:26prioritization.
27:27Uh this was also used um
27:31uh in without the numbers and I'll show
27:34you an example in a minute. So that
27:35front uh side looks at the hazards. So
27:39it explains to the to the people
27:41involved, the workers or the
27:42supervisors, these are the things that
27:45impact on heat stress. It's not just
27:47about temperature.
27:50We then say okay temperature is does
27:52play a role. So we as I mentioned the
27:54parent temperature nice and simple just
27:56temperature and humidity and then of
27:58course metabolic work rate. How hard are
28:01they working? Are they just using a
28:02clipboard and ticking off um some boxes
28:06and checking some meters or are they out
28:08there digging trenches and that that you
28:10know makes a quite a significant impact.
28:14And of course
28:16as they tick all these boxes what we
28:18would say to them is anything in this
28:19box with a marked with a three then that
28:22was something that we needed to control.
28:24Uh something had to be done straight
28:26away basically. Uh so that was a
28:28priority. So that was the the idea
28:30behind the 0123. It prioritized what we
28:33needed to do. And as I mentioned there
28:37was it also appeared in a version
28:39without any numbers on it just purely
28:42colorcoded green, yellow, amber or red.
28:46And if it was in red again you have to
28:49do something about that straight away.
28:50If it's in uh in moderate then we need
28:54to think about doing something and so
28:56on. So it was nice and simple and it it
28:59relayed to the worker that
29:02heat stress was not just about
29:04temperature.
29:06And then of course where would we be
29:09without modern technology? This has been
29:11picked up and you can actually get this
29:13model as a uh a free app if I think it's
29:17available both in Android and uh uh an
29:20Apple version, iOS version. It's exactly
29:23what I've just shown you except it's uh
29:26in an app and it's been um up upgraded a
29:30little bit in that it also gives you
29:33suggested risk controls. The questions
29:35as you can see are exactly the same. It
29:38gives you a result with that red um uh
29:42red statement will tell you what how you
29:45know how how significant the risk is.
29:48And then if you look at the the third
29:50box here, the little numbers the the you
29:53know the a red three indicates it's
29:55something that needs to be done quickly
29:57and so on and the total assessment and
29:59then some controls. So this is readily
30:01available. It's free. It's free to be
30:04for download and anybody can use it. I
30:07believe that there's also similar thing
30:09uh the AIHA have a WBGT version that you
30:12can also download.
30:14Another model that we've used uh this is
30:17uh this is only something new in
30:18development. Um some of you will be
30:21familiar with um the National Weather
30:23Services heat uh heat stress index chart
30:27uh which has been around for many many
30:29years. It's a color chart that uh just
30:32temperature and humidity and uh gives
30:34you a risk assessment. So
30:39this one only requires knowledge of air
30:41temperature and humidity. But although
30:44it looks simple, this one is based on a
30:48rational index. So behind it, uh there
30:51is quite a lot of um uh calculation and
30:54assessment. The original um National
30:57Weather Service heat stress chart was
30:59based on um um meteorological data and
31:05the
31:06uh the the actual risk assessment side
31:09of it. there wasn't a lot of effort put
31:11into that side of it. More of the effort
31:13was put into the u uh the the
31:16meteorological side. So what this has
31:18done is it's taken that concept but put
31:21uh more effort into the uh risk
31:24assessment and it uses ISO 7933
31:27to uh to to calculate that risk. So all
31:32we look at first off is all they just
31:34have to identify the temperature and the
31:35relative humidity which is you know
31:37pretty easy to get hold of whether you
31:39use a cychrometer and instrument or you
31:42can get it off often enough websites.
31:44You then have to assess the task. So the
31:47metabolic workload and to make life a
31:49little bit easier,
31:51what we had had done is we created a
31:54table and this was done for a um I think
31:58this was for a a council of u that had a
32:02number of different tasks and you can
32:04see rather than getting too complex with
32:07numbers and whatever we just basically
32:08said look you know if it's a low it's
32:11you know work associated with traffic
32:13control administrative tasks and so on
32:15all the way through to you know
32:18construction crews intensive armwork. So
32:20they don't have to um again have a lot
32:24of technical knowledge. They just need
32:25to know what sort of task they're going
32:27to be doing and it gives them a low,
32:29medium or high rating.
32:32Then with that what they would do is
32:34they would go to these charts and each
32:37of these charts you see this is a low
32:39workload chart. This is a medium
32:41workload chart and this is a high
32:43workload chart. And depending on which
32:45one they were doing. So if for example
32:47they were the task came out to be a
32:49medium workload, they knew what the
32:51temperature was. It was 37° centigrade
32:55and humidity was 45% humidity. Okay,
33:00that's an amber color. So all they would
33:03do from there is then go to what we
33:06would call our heat stress response
33:08guide. And the heat stress response
33:10guide basically tell tells them what
33:12they have to do. So this is a um an
33:15amber color. Okay. So for an amber
33:17color, everybody on the work site, they
33:20have to know what their level one
33:21response plan is. They have to schedule
33:23breaks. There's temperatures for less
33:25than 40, increase ventilation and so on.
33:28And then it also that was for the
33:30workers. It highlights what the
33:31supervisor has to do. It highlights what
33:33the health and safety advisor has to do.
33:36And even to the point where it says this
33:38is what the the site manager needs to be
33:40needs to do. So the intent behind this
33:42was it was designed to provide the
33:46information to the the front line for
33:49people that don't have that technical uh
33:52advice readily. So this is just one of
33:54the other methods that was used.
33:56So if we do that and we end up with a
33:58situation that says right now we've got
34:00a significant risk here. We need to do
34:02more about it. So this is where we call
34:04in the hygienist or the occupational
34:07health and safety professional. So, we
34:09need to do some additional monitoring.
34:13If you're going to do any monitoring of
34:15heat stress, I'll stress you must at a
34:18minimum take these four readings. Dry
34:21bulb temperature, your black globe
34:23temperature, your air velocity, and
34:25humidity. You need those four readings
34:28if you're going to do any kind of a
34:30decent assessment of a heat stress
34:32environment. Don't try and do it without
34:34those at least those four.
34:37You'll also need to think about
34:40metabolic load and clothing because
34:42again they all play a role. So for the
34:44level two assessment, we collect this
34:47data and then we use that data. So how
34:50how are we going to use it? We'll put it
34:52into a rational index and I'll take you
34:54through that process right now. Right
34:57now when we assess a working heat stress
35:00work environment, there are two
35:02approaches being used out there. The
35:04first approach is limiting the work to
35:08suit the environment or the risk. So
35:10this is a common one that's used where
35:12we develop work rest regimes for the for
35:15the workers. Okay, you're going to go
35:17out there, you're going to work for 30
35:18minutes, then you're going to rest for
35:2030 minutes or work for 45 and rest for
35:2215 or whatever. So it's very
35:24administrative in its control.
35:27The second approach, which is the one I
35:29prefer and the one I tend to teach, is
35:31[snorts] modifying the task or the
35:33environment to reduce the risk. And this
35:36falls back on our um hygiene training
35:40which says we should use the hierarchy
35:42of controls. So start at the top and
35:45work your way down. If you can eliminate
35:47it by changing it the task timing to the
35:49night shift rather than a day shift or
35:51or whatever and then engineering
35:53controls that's the your preferred
35:55approach. So they're the two approaches.
35:58So the approach taken will determine
36:01your assessment method and that's pretty
36:03obvious.
36:05So if we look at the indices
36:08uh that you can use,
36:11we start to look more towards a
36:13quantitative approach. So we're now
36:14getting out there and we're measuring.
36:16The first level approach there was less
36:20measurement. It was more qualitative.
36:22Here we're starting to take measurements
36:24and doing we're going to do some
36:25calculations.
36:28So we're going to use thermal indices
36:30for the assessment situations.
36:34Now a heat stress index is supposedly a
36:38single number that combines the effects
36:40of key factors in any thermal
36:42environment. And in the early days, this
36:45this was a single figure. In more modern
36:48times, we're starting to see that the
36:51indices provide more information. And
36:54we're starting to see sort of a um uh a
36:57continuum of data rather than a single
37:00piece of data and it talks about the
37:02thermal strain that the person feels.
37:07So there's a couple that I'll that uh
37:10well there's more than a couple. There
37:11are quite a number out there. There's
37:12thermal work limit. There's PHS uh uh
37:177933.
37:19Uh there is u UTC UC universal comfort
37:24UTC universal thermal comfort index
37:28which is I always get that one wrong. Um
37:31and there are a number of others that
37:33are out there that you can use. I don't
37:36have time to go through all of them.
37:37I've picked these two because these are
37:39two that uh are the most common and the
37:41ones I to be quite honest the two that I
37:43know the best. Um so they look at
37:46climate characteristics, they look at
37:48the clothing of the workers and they
37:50look at their metabolic rate. So what
37:52we're looking at here is
37:55the the heat balance equation and
37:58everything keeps coming back to that
38:00heat balance equation. So that's one of
38:02the reasons that these indices are so so
38:04useful. So what it does is it takes that
38:08data and it uses predicted responses of
38:11the body such as sweating and elevated
38:13core temperature to give us an
38:16understanding of the the strain on the
38:18body.
38:20Um so to extend this usefulness rather
38:23than just using thermal characteristics
38:26uh we're now starting to look at uh
38:28insulation effects of clothing included
38:30in the calculations.
38:33So just very quickly the thermal work
38:35limit some of you will be familiar with
38:37this others may not uh was developed in
38:39Australia and tested in a number of
38:41mining scenarios both uh in open cut and
38:45underground.
38:47The index is designed specifically for
38:49self-paced workers. So they have to have
38:51that ability to self-pace. And one of
38:54the benefits is it doesn't rely on the
38:56estimation of actual metabolic rates.
38:59And you'll see when we look at predicted
39:00heat strain, you need to estimate what
39:03the metabolic rate is in the thermal
39:06work limit. You don't need to know that.
39:09Now work measures, work areas are
39:11measured, excuse me, and characterized
39:14based on the metabolic heat balance
39:16equation.
39:18And then you end up with a figure. So it
39:20may be, you know, 150
39:23watts per meter squared or whatever. and
39:26that can be related to a set of defined
39:28parameters and from that you go to a
39:30table which gives you an indication of
39:32the sorts of controls you need to be
39:34looking at. Calculating the TWWL is
39:37actually quite complex
39:39and this is one of the very early
39:41versions and this may have changed a
39:43little bit since this first came out but
39:45you can see uh the inputs of relative
39:49humidity, air temperature, globe
39:51temperature all barometric pressure and
39:53relative. So there are a number of
39:55parameters that you would input and you
39:57would end there up with these outputs.
39:59For example, a thermal work limit watts
40:01per meter squared of 124 and and that
40:05you would relate back to that table. Um
40:08this was a version that was available
40:11many years ago uh 200
40:152006. So we're going back 20 years. I
40:17think it's still available on the
40:19internet if you really go hunting for
40:21it. But uh it's not that um easy to
40:25find. Some instruments you can actually
40:28buy these days that have it built in. So
40:30for example, the Kaw uh and the Kestrel,
40:34you can these instruments actually have
40:36thermal work limit built in and they
40:38will calculate it for you. And you can
40:41also go to websites that you enter your
40:43data and it'll give you a figure.
40:45There's just one example that I found
40:47when I did a bit of a hunt through. You
40:49click on that one. This comes up. You
40:51put in those those four parameters and
40:53it gives you an approximate thermal work
40:55limit. You then take that thermal work
40:57limit and as I said this is a very
41:00simple table that you would relate it
41:02to. So if it's less than 115 you've got
41:07withdrawal zone is extreme and it gives
41:09you specific controls that you can use.
41:13uh and then as the figure gets higher
41:17then it's less and less of a risk and
41:19the controls aren't as as severe or
41:22significant. So that's the thermal work
41:24limit. Um that's quite popular in the
41:26Middle East now and it's used quite a
41:28bit uh in Australia as well, not as
41:31popular in other countries in the
41:33northern hemisphere.
41:35Now the other model that I tend to use
41:38the most is predicted heat strain and
41:40this is this is based on the ISO
41:42standard 7933
41:44originally developed in 2004.
41:48Uh it evolved from Belding and Hatches
41:50heat stress index which they put
41:53together in 55 1955. So we're going back
41:56a bit. Quite a significantly different
41:59model now than what was developed by
42:01Belding and Hatch.
42:04uh it uses the environmental and task
42:06parameters in a num quite a number of
42:09occasions and it's a quite a significant
42:11number of algorithms. If you have a look
42:14at the actual ISO 7933 standard uh and
42:18if you're keen enough to read through
42:20that standard you will see how um how
42:24comprehensive and how many of the
42:26algorithms there are there. It is very
42:28uh very uh complicated and in the early
42:33days when it first came out some of us
42:35were you know that were keen got in
42:38there and actually did the calculations
42:40which took literally took hours. These
42:43days there are apps and all sorts of
42:45things available to do the calculation
42:47for you. It's a very useful tool. I like
42:50it because it allows you to look at
42:52control strategies not just looking at
42:54the strain and the individual. A lot of
42:57the other parameters look at the comfort
42:58of the individual uh or they they point
43:01you towards work restress regimes. This
43:04allows you to actually look at controls
43:06and I'll show you some examples shortly.
43:09And it also allows you to look at
43:11several different phases and this is
43:13very helpful particularly when you think
43:15about
43:17uh a work rest regime. So what we can do
43:20with the ISO standard is it allows you
43:23to go in and say, "Okay, for an hour
43:26they're going to be working in an
43:28environment of, you know, 42° at at 57%
43:33humidity and air velocity of 0.1. But
43:36then after that hour, they're going to
43:38spend 20 minutes sitting in a a cooled
43:41environment uh such as an air
43:44conditioned uh crib room or lunchroom
43:47which is going to be 24°
43:49and and relative humidity of 20% and
43:53whatever. And then they're going to go
43:54out after that 20 minutes and spend
43:56another hour out there. So you can input
43:58this data and it'll it'll do that an
44:02approximate assessment of the impact of
44:04those different phases and that can be
44:06quite important because some of the um
44:09uh the tools that we use for example
44:12WBGT
44:14assumes in its simplest form assumes
44:17that the the rest is taking place in the
44:20work environment which is often not the
44:23case. Now um but that is of that is
44:26basically how it is used. So you need
44:28this gives you the opportunity to to
44:30modify that and play with it a little
44:32bit. It is a powerful tool but it's not
44:35suitable for the non-technical user and
44:37people can get very confused in using
44:40it. So you need to understand its use.
44:44Again there are tools available out
44:45there. Instruments uh there are not a
44:48lot of instruments that will calculate
44:49it. This is one I found on the internet
44:52called the LSI last last heat shield. Uh
44:57it it calculates the predicted heat
44:59strain. Uh I like to go to this site.
45:03This is the um uh habit habitat science.
45:08Uh it's from the uh the fame group from
45:11the University of the I think it is. Uh
45:16it is quite complex. Uh this one is
45:18based on the 200
45:21I think 23 ISO 7933. So it does start to
45:26ask you for things like moving speed,
45:28theta angles, reflection coefficients.
45:31So you need to do a little bit of
45:32homework in that area. But this is a
45:36really useful tool and you can plot uh
45:38predicted rectal core temperature,
45:40rectal temperature, core temperatures,
45:42skin temperatures and water losses. So
45:45very useful tool.
45:47There is another app available. This
45:49used to be available in Android and uh
45:53Apple versions. Unfortunately uh the
45:55funding ran out for this app and it's uh
45:59and hasn't been updated. It is still
46:01available in uh on for the Apple phone
46:06uh and it is in uh but it I need to
46:08stress it is based on the 2004 version
46:13of ISO 7933. So, it's a simpler version,
46:17so it doesn't have the some of the
46:18corrections in the later versions, but I
46:21still find it very useful. I have this
46:23on my phone, and if I'm out in the
46:25field, I can do with my uh monitors, I
46:28can do some quick assessments out in the
46:30field, and it gives me an idea of what's
46:33happening. And if I really need to be
46:34more precise, when I get back to my
46:36office, I can start crunching the
46:38numbers with the the more upto-ate
46:40versions. To give you an idea of what it
46:43looks like, you have a screen where you
46:45input your data. How long is the the
46:49phase going to be? Uh the drop downs of
46:52metabolic rate, whether there are
46:54climatized and so on and air
46:56temperature, globe temperature, relative
46:58humidity and so on. And then it'll do a
47:01uh do a calculation for you and it will
47:03tell you at the bottom here uh you know
47:05core temperature of 38 degrees is not
47:07exceeded water loss of 7.5% or so on um
47:11you know not exceeded. So in this case
47:13there wasn't an issue and it also
47:16produces some nice graphs for you. So
47:18you can see this one is the predicted
47:19core temperature of the individual and
47:22you can see it plateaus off and it sits
47:25below 38° which is um our cut our cutff
47:29we use. So this one indicates that that
47:32task is not a strenuous one and it even
47:35lets you know an approximation of how
47:38much fluid will be lost in that period
47:41of time. So it's quite a useful tool
47:44and I'll show you how I use uh this in a
47:46minute.
47:48So
47:50let's have a look at act some actual
47:52hands-on use of some of these tools
47:54rather than just u screenshots. So
47:57here's an example. So we got a scenario.
47:59So we got an emergency services member
48:02is attending a potential spill scenario
48:05in a chemical store room which is an
48:08unventilated shipping container. And if
48:10any of you have been to mine sites and
48:13uh some industrial sites, the shipping
48:16containers are quite commonly used for
48:18storage and for all sorts of things. So,
48:20they're a common site. Now, this task is
48:22estimated it's going to take
48:23approximately 2 hours to clean up, but
48:26it may take longer. Now, to save you
48:29some time, we've done the the the
48:32level one assessment, and the level one
48:34assessment tells me that we're going to
48:35have some real issues here. So, I need
48:37to go out and do some monitoring. So I
48:39take my trusty monitor out and these are
48:42the results I come back with. So my dry
48:45bulb temperature is roughly 40.9
48:48centigrade or 106.
48:50Globe was 45.3 114. Relative humidity
48:5522. Air velocity 2 m a second. Metabolic
48:59load 175. So that's a pretty decent uh
49:04work rate. posture. They're going to be
49:05standing and they're wearing single
49:07layer disposable cotton overalls. And
49:09you can get this uh point. 0 clo factor.
49:12Most of the uh
49:17the programs you can get. I've got drop
49:19downs which show these different figures
49:21or there's also an ISO standard where
49:23you can pull this out and it's an
49:24acclimatized worker. All right. So these
49:27are the parameters. And it's also good
49:29when you collect this data to do a quick
49:31eyeball of it because that can give you
49:34some uh some tips as to what our issues
49:37may be. And if we know what our heat
49:40balance equation tells us, then you you
49:42should be able to pick up straight away
49:44by eyeballing this that we are going to
49:45have a problem and where the problems
49:47are going to occur and where our
49:49controls can come from.
49:52So we plug our data into the um in this
49:56case I've used the app just just to be
49:59for simplicity sake. So you can see 2
50:02hours hand arm trunk work they're
50:04acclimatized they can drink freely
50:06they're standing the point8 underpants
50:08shirt overall socks and shoes air temp
50:11globe temp relative humidity and air
50:13velocity we plug them all in this is
50:15phase one and we calculate and this is
50:19what we get. So it produces this graph.
50:21So we look at the graph and we say well
50:22okay what is that telling us? Well if we
50:25look carefully
50:28at 38 core temperature of 38° is reached
50:33within 70 roughly 79 80 minutes
50:35thereabouts. So therefore we have a
50:38situation where we know the individual
50:41is going to be under some significant
50:42thermal strain. So
50:45do we need to do anything about it? Yes
50:47we do. we can't have that person working
50:50in that environment under those
50:52conditions because eventually we could
50:55end up with a significant heat illness
50:58such as a stroke. So the usual response
51:01is well
51:03let's give them a 30 minute rest break
51:05and as I mentioned before rest breaks
51:07can sometimes be in the work
51:09environment. So we're going to say okay
51:12after that 2 hours take 30 minutes off
51:14sit down have a break you know and just
51:16relax take it easy and see if you see
51:18how you recover. So we're allowing them
51:20to have a 30 minute rest break and this
51:24is what happens. So 30 minutes resting
51:28in the work environment
51:30the temperature drops to 38.1.
51:34So that third that break in the work
51:36environment is not really acceptable. So
51:40so we need to do something else. So what
51:43if we gave them a 30 minute break in an
51:45air conditioned room? And often you say
51:47oh there's you know when are you going
51:48to you're not always going to have an
51:50air conditioned room available but
51:51sometimes you have your vehicle people
51:53have vehicles available which have air
51:55conditioners in them. Others do have
51:57recir have recovery rooms. I did some
52:00work at a smelter where they built um
52:04portable recovery rooms which was
52:06basically a 2 m by 2 meter hut on the
52:10forklift uh tines and they had a uh a
52:15drink f chilled drink fountain in there
52:17and an air conditioner and they would
52:19move that thing around to the work site
52:21plug in a hose plug in the power and
52:23they had a recovery rim. So as simple as
52:26that. So what's the benefit of having an
52:29a break in an air conditioned room?
52:32That's the benefit. As you can see here,
52:35resting in that work environment,
52:37very poor in the for a period of time,
52:40you get a very poor drop in core
52:42temperature. But as you can see from
52:45resting in a that same period of time in
52:48a cool environment, you get a
52:50significant drop.
52:52So, the importance of having a cool
52:54recovery area is highlighted. And this
52:57is I actually use this as a a
52:59justification for to get a recovery room
53:02put onto one of the sides. So, you
53:04think, "Oh, that's great." So, the
53:06temperature's down to 37.3.
53:10Fantastic. Let's send them back out to
53:12work. So, off they go back out to work.
53:15Right.
53:17So 30 minute break after 120 minutes in
53:20the cool room and then back to work. So
53:22is this going to do the job?
53:25Well, sort of. But
53:29look what happens.
53:31So they've had their rest, but all of a
53:33sudden they reach that limit very
53:35quickly.
53:36So that 30 minute break after 120
53:39minutes in a cool environment although
53:40it drops the core temperature down below
53:44it doesn't take them very long for it to
53:46come back up and this the more times
53:49they do it the quicker it actually gets
53:51up. So we need to think about what
53:54happens excuse me when [clears throat]
53:55they go back out there. So if we look at
53:58it and we say well what could we do
54:00here? Well, what if we say hm let's see
54:03what if we gave them a break at around
54:05about [snorts] 60 minutes just before it
54:08hits 38 and we gave them a rest then. So
54:11we're looking about here. So a 20 minute
54:14break after 60 minutes and then back to
54:17work
54:18and then that this is what happens. So
54:20you will see gets up around about 60
54:24minute mark and then we give them the
54:25break drops off and then it comes back
54:27up again but it's staying below 30 38°.
54:31So
54:33we're using the tool to give us a a more
54:36confident a little bit more confidence
54:38in our work rest regimes. Now
54:42I don't want you to think that these are
54:45precise tools.
54:47They're guides. There's still only
54:49guides, but they're giving you a better
54:51understanding of the work rest regime
54:53and how to plan it. So, that was that
54:55first model we talked about changing um
54:58it's the administrative control. But
55:00what about the second model where we
55:02change the work environment to to lower
55:05the risk? And as I said, my preferred
55:07approach.
55:10So, let's assume
55:12uh we're looking at engineering
55:15controls. And if you think back to the
55:16when we did the monitoring, one of the
55:19things that came up was the air
55:21velocity. Remember the air velocity was
55:230.2 m a second. Now 0.2 m a second is b
55:28barely air movement. There's hardly any
55:30movement at all. So what if we bumped up
55:33that air velocity to 1 m/s? So a factor
55:36of five. So we're going from 02 to 1
55:39m/s. What impact is that going to have
55:42on the work environment?
55:45So this is the impact it has and you can
55:48see the core temperature climbs then it
55:52gets to about bit about 379 and then it
55:55flattens off
55:57and it's leveling off. So it's obviously
56:01going to reduce the impact.
56:04So why is it reducing the impact? So
56:07what's happening basically go back to
56:09our heat balance equation. the work the
56:12work environment is in is increasing the
56:14core temperature. But by increasing the
56:16air velocity, we're increasing the
56:19ability for the body to evaporate sweat.
56:22As we evaporate more sweat, we get a
56:25better cooling effect which cools the
56:27peripheral and the blood in the skin and
56:30so on and helps reduce the core
56:33temperature. So one of the better
56:35controls would be to increase the air
56:38flow. So this is one one way we can go
56:40about it.
56:43Another aspect is the looking at the um
56:46the radiant heat. So what if we put in a
56:49radiant shield you know shade cover to
56:52reduce the globe temperature. Similar
56:54sort of thing can happen. You can see
56:55here we get a drop off of the uh the
56:59predicted core temperature. But notice
57:01this one doesn't level off. So
57:02eventually we would still have an issue
57:04here. But if you combined a radiant
57:07shield with an increase in air velocity,
57:09you're going to get a much better
57:10effect. So these are how we can use
57:13these tools.
57:16But there's a few things to consider
57:18when you're using the indices.
57:21And there's often more to the index that
57:24meets the eye. So some indices require
57:27an estimation of metabolic load. And we
57:29saw predicted heat strain, heat stress
57:31index, and WBGT. You have to give an
57:34estimation of the metabolic workload and
57:37sometimes there can be an error involved
57:39there.
57:40There are assumptions made in relation
57:42to evaporation and sweat rates in the
57:44rational indices. So we need to be
57:46cautious there. And also some rational
57:49indices have different li limiting
57:51parameters. TWWL uses a core temperature
57:54of 38.2 as a limiting factor whereas
57:57predicted heat strain tends to use 38 or
58:00if you wanted you could use 38.5.
58:03And finally, rational indices rely on an
58:06allocation of an insulation value for
58:08clothing. Some may be varied and some
58:10are fixed. So you have to understand the
58:12clothing as well.
58:16So some underlying assumptions also with
58:18indices whether they be rational or
58:21empirical or even the direct indices
58:25indices in the main assume fit young
58:28acclimatized individuals.
58:31So you have to think does this reflect
58:33the modern workforce? Now I do a lot of
58:35work or have done a lot of work in the
58:37mining industry and I can tell you now
58:40that in the mining industries they're
58:42not all fit young climatized
58:44individuals. So you need to keep that in
58:46mind. They assume they are well hydrated
58:50with access to fluids. And again is this
58:52really the case in the workforce? Yes,
58:54in some workforces they do have a very
58:57good education and a very good culture,
58:59but often they don't.
59:01And things like the empirical indices,
59:03effective temperature, basic effective
59:05temperature, corrected effective
59:06temperature, predicted for our sweat
59:08rate are based on nomograms from
59:11subjective assessments. They are more
59:13comfort indices rather than heat stress
59:16indices. So none of these indices no
59:18matter how how complex they are can
59:21accurately estimate the microclimate
59:23inside high level impermeable clothing.
59:25So that's something you need to keep in
59:27mind.
59:28They have their own microclimates.
59:31So what do we use?
59:34Wet bulb is often referred to in
59:35industry and I've seen still use in
59:37industry to to this day. Some regulators
59:40use effective temperature and I know of
59:42one mining um regulator in Australia
59:45that still uses effective temperature.
59:48Others use WBGT.
59:51WBGT is very popular in some countries
59:54but it has limitations but it is simple
59:57to use as a screening tool. So as a
1:00:00first level screening tool WBGT can be
1:00:02quite useful. The rational indices are
1:00:05complex but they are more powerful and
1:00:08can be used to identify suitable
1:00:10controls and that's where I find them uh
1:00:13the a great benefit.
1:00:16And I mentioned physiological
1:00:18monitoring.
1:00:20You've probably come across some of
1:00:21these at some stage. If you haven't, you
1:00:23will. I can guarantee it. To the left
1:00:25there we have one of the early models
1:00:27and to the right some of the the more
1:00:29modern ones.
1:00:31So when do we use it? when the allowable
1:00:33exposure time is short, so less than 30
1:00:36minutes, when we've got high PPE or
1:00:38encapsulating suits required.
1:00:41Now, these physiological monitoring
1:00:44um units, they should be used to
1:00:47complement tier one and tier two, not to
1:00:49replace them.
1:00:51So, what do we measure? There are
1:00:54numerous things we can measure. heart
1:00:55rate, core temperature. Uh sometimes
1:00:58they're used for body mass water loss,
1:01:01saliva osmolality, urine specific
1:01:04gravity, urine color. So there's quite a
1:01:06a long range, a large range, sorry.
1:01:10And why it matters is because we set up
1:01:12tomorrow's predictive systems. We're
1:01:13using them to to [snorts] see how the
1:01:16body strain is reacting and how to
1:01:18predict what controls to put in place in
1:01:20place. And the real-time alerts can be
1:01:22very very useful before those limits are
1:01:25reached. It also takes a focus to the
1:01:28individual. So this is where we need to
1:01:30be careful. So it's not average risk.
1:01:32It's not a herd measurement. It's an
1:01:35individual measurement. And it can be
1:01:38the technical base for the some of these
1:01:39predictive systems.
1:01:42And just very quickly some of the
1:01:44parameters that have been used, heart
1:01:46rate, recovery rate, body core
1:01:48temperature, and as I mentioned,
1:01:50specific gravity, saliva, body water
1:01:53loss.
1:01:55But bear in mind though, physiological
1:01:57monitoring still relies heavily on
1:01:59administrative controls and that can be
1:02:02a failing.
1:02:05This is an example.
1:02:07Here we have a physiolog physiological
1:02:09monitoring result. So our little white
1:02:12graph here is core body temperature. The
1:02:17uh pink or purple as you can see is the
1:02:21heart rate and you can see the sustained
1:02:23heart rate here is quite high as is the
1:02:25core temperature.
1:02:27Now this is great cuz you know it's real
1:02:31time and it's monitoring the individual
1:02:32and this is what people are now trying
1:02:34to sell you to say this is the answer to
1:02:36the the problem. Put real-time monitors
1:02:39on people. But let me show you a little
1:02:41problem with them. See this line down
1:02:43the bottom here? This red line,
1:02:46that's an alarm.
1:02:49And on this particular individual, the
1:02:52alarm went off right at the start here.
1:02:55And they initially acknowledged it and
1:02:57took a break. And you can see where they
1:03:00took their break.
1:03:02And they got this little yellow bit in
1:03:04here which said, "Yep, they could go
1:03:05back to work." And they went back to
1:03:07work. reckon the alarm almost went off
1:03:09straight away. And what did they do?
1:03:11They ignored it. And when asked at the
1:03:14end of the shift why they ignored it,
1:03:17well, the job had to be done.
1:03:20So whilst these are great tools, you do
1:03:23have to have the right culture and the
1:03:25right procedures and policies in place
1:03:27and the right education. You can't just
1:03:29buy one of these tools off the shelf,
1:03:32give the device to someone and say,
1:03:34"Here, use this for your heat stress.
1:03:38peer pressure, production pressures,
1:03:40they can play a pretty important part in
1:03:42it as well.
1:03:44So the benefits, it provides an accurate
1:03:47measure of core temperature and heart
1:03:48rate. It allows real-time monitoring of
1:03:51the individual's response to heat stress
1:03:53and when controls are needed. It
1:03:55provides more relevant information when
1:03:57impermeable clothing is worn because of
1:03:59that microclimate
1:04:01and can be used to identify early
1:04:03warning signs of heat strain for for a
1:04:05timely intervention. So they got some
1:04:07real benefits and they can incorporate a
1:04:10number of physiological parameters at
1:04:11the one time for assessment. Some of
1:04:13these monitors look at just one thing
1:04:15core temperature or heart rate or sweat.
1:04:19Others combine these different
1:04:21parameters into an algorithm and do a
1:04:23calculation. So that it be quite useful
1:04:25there. There are some disadvantages. The
1:04:28responses to history vary among
1:04:30individuals. So interpreting the
1:04:32physiological data does require some
1:04:34expertise.
1:04:36Data quality is dependent on the correct
1:04:38use and maintenance of the equipment
1:04:40where it's positioned how it's used
1:04:44and as you just s you just saw it can be
1:04:47ignored when production and peer
1:04:48pressure exists
1:04:51and where is can ignore other signs and
1:04:53symptoms based on the monitor
1:04:54information. So the monitor says I'm
1:04:56still doing well but if I'm not feeling
1:04:59well they can ignore those symptoms and
1:05:02you need to be careful there.
1:05:05And as I mentioned, they're ineffective
1:05:07if an organization does not have the
1:05:09correct management systems and culture
1:05:11in place. They're very important
1:05:14and uh a big one these days there may be
1:05:17issues with data privacy laws in some
1:05:19jurisdictions. And I know one company I
1:05:21did some work with global company they
1:05:24were you the their their server was
1:05:27based in one country they were
1:05:29monitoring in another and there were
1:05:31issues with privacy laws. So you need to
1:05:33be aware of that.
1:05:35My bottom line here is these are great
1:05:38tools but they are not standalone
1:05:40systems and they should be used in
1:05:43conjunction with a robust heat stress
1:05:45management program. Very important.
1:05:50All right. And just very quickly to
1:05:52touch on some concepts again you
1:05:54probably know a great deal about this so
1:05:56I won't delve in too deep. Hydration.
1:06:00I always touch on this because I've been
1:06:02to too many sites when you say, "Show me
1:06:04your heat stress management plan." And
1:06:06they give me a hydration management
1:06:08program. A hydration management program
1:06:10is an important part of a heat stress
1:06:13management program, but it is not the
1:06:16heat stress management program.
1:06:20Um, it's difficult to give specific
1:06:22guidance because there's so many
1:06:24variables.
1:06:25General guidance for personnel and this
1:06:28can vary a great deal depending on the
1:06:30amount of exercise 04 to 08 liters per
1:06:34hour during work or exercise but they
1:06:36can range between.5 to 2 L depending on
1:06:40the intensity
1:06:43rule of thumb when is more water
1:06:46required increased metabolic work rate
1:06:48increased sweating personnel working in
1:06:50the sun or in areas of sources of
1:06:53additional rad convective
1:06:55additional illnesses associated with
1:06:57losses. And of course, if you're
1:06:59acclimatized, you will sweat more than
1:07:01someone who's unaclimatized.
1:07:03And the good old one about caffeine,
1:07:07um there's a bit of a fy that says, "Oh,
1:07:09you shouldn't be drinking tea or coffee,
1:07:11and caffeine is a diuretic." Uh well,
1:07:14this was based on a study many years
1:07:16ago, which wasn't really 100% right.
1:07:19There were some limitations to that
1:07:21study. More recent studies have found
1:07:23that yes, caffeine it can increase
1:07:26non-sweet fluid losses in some people
1:07:29and in some individuals and depending on
1:07:32what they are doing and it's more common
1:07:34in less active individuals than in
1:07:36active individuals.
1:07:39So for example, a weak cup of tea can
1:07:41add to the overall fluid uptake of the
1:07:44individual more than the uh any diuretic
1:07:47effect is going to have. But bear in
1:07:50mind that excessive caffeine is still
1:07:52going to be an issue uh with insomnia,
1:07:55gastrointestinal upset, tremors, and in
1:07:57some cases even teocardia.
1:08:02Um this is just a table I dug up out of
1:08:05the internet just out of interest. You
1:08:06can see some of the the caffeine levels
1:08:09per 100 mil. So um just out of out of
1:08:12interest there is some significant
1:08:14levels of caffeine and some of these as
1:08:16I said will affect some people.
1:08:20The other one to bear in mind is drugs
1:08:22that can impact with thermmorreulation.
1:08:26We are learning more and more about
1:08:27prescription drugs that can impact and
1:08:30you need to be conscious of this
1:08:33centrally acting drugs. They disrupt
1:08:35hypothermic thermmorreulation.
1:08:38you know pheninoioines
1:08:40butyricenones
1:08:42drugs with anticolinergic activity so
1:08:45they can block sweat gland excretion
1:08:47these are things like belladona
1:08:49antiparkinson antiscychotics
1:08:52um triccyclic anti-depressants
1:08:55antihistamines you know all these drugs
1:08:58that can have an impact and um the uh
1:09:01this is one that always stumps me the
1:09:03sympathy
1:09:05can cause narrowing of blood vessels in
1:09:07the skin So, epinephrine and ephrine and
1:09:10those sorts of things. So, be aware that
1:09:12people on medication can it can impact
1:09:14how they manage heat stress. And of
1:09:17course, recreational drugs. Alcohol has
1:09:19a geretic diuretic effect, increasing
1:09:22risk of dehydration. Cocaine and
1:09:24fetamines, MDMA can elevate body
1:09:26temperature and this can result in vaso
1:09:30constriction, decrease body flow etc.
1:09:33And of course increase muscular activity
1:09:35which can increase body heat.
1:09:40Climatization
1:09:41obviously some people can go from a work
1:09:44environment to a hot dry humid climate
1:09:47to um very humid environments.
1:09:51Climatization is a process whereby the
1:09:54body helps us adapt to that external
1:09:56environment.
1:09:58It's a complex physiological response
1:10:00that helps us with increased tolerance.
1:10:02and I'll show you how in a minute. Um,
1:10:06where it's not present, the potential
1:10:07for an individual to suffer from a heat
1:10:09related illness increases. So, you need
1:10:11to be conscious of that fact and we need
1:10:14to ensure we ease into our workloads for
1:10:17those that are underclimatized.
1:10:20Um, this is one of my favorite graphs
1:10:22from a uh a book called um sport and
1:10:28physical activity in the heat. Uh it's
1:10:31edited by Cassa. It's quite a good book
1:10:34good book if you can get your hands on
1:10:35it. And it's a graph that shows you um
1:10:38the uh the body's response to
1:10:40climatization. And you can see here, you
1:10:43know, things like the sweat rate, it
1:10:46increases, plasma volume increases,
1:10:49thermal comfort increases, exercise cap
1:10:52capacity increases, we get drop off of
1:10:55heart rate. And these all occur, the
1:10:58majority of them occur within 7 to eight
1:11:00days. The um a full acclimatization
1:11:04tends to work over that 14-day period,
1:11:06but a great deal of it occurs in that
1:11:09that first week or so. So, climatization
1:11:12plays an important role in tolerating
1:11:14heat.
1:11:18The hierarchy of controls I touched on
1:11:20earlier on. Don't forget the hierarchy
1:11:22of controls. look to control the work
1:11:25environment first before you start going
1:11:27to administrative controls and PPE. I
1:11:30did some work on a a um a a laundry that
1:11:34was built in northern Australia. It was
1:11:37designed in southern Australia for a
1:11:38cool climate. It was built in the
1:11:41northern climate which is hot and humid
1:11:43and it was totally unsuited. It didn't
1:11:46have operable windows. It didn't have
1:11:48louvers. It didn't have a ventilation
1:11:50system. So totally um unsuited to the
1:11:54environment. By simply adding uh
1:11:56louvers, operable windows, putting um uh
1:12:01um what we call whly birds or
1:12:03ventilators on the roof, we we were able
1:12:05to create what we call the chimney
1:12:08effect and we'll be able to get air
1:12:10movement in there which helped the um
1:12:13the temperature within the building
1:12:15quite considerably. So look to
1:12:18controlling the work environment first.
1:12:20Another one that I find very useful is
1:12:22the vortex tube. I'm not sure if you've
1:12:24come across this. It does have
1:12:26limitations in that it's used when uh
1:12:30you have to have compressed air to use
1:12:31it. Basically, where I found this very
1:12:34useful is um particularly with boiler
1:12:36makers working in enclosed confined
1:12:38spaces or welding in vessels or air um
1:12:43uh sand blasting and and the like where
1:12:45they they've got compressed air units.
1:12:48The
1:12:49vortex tube is basically a portable air
1:12:52conditioning unit. So the air goes in,
1:12:55it is spun at a very rapid rate which
1:12:58splits the air off into two streams, a
1:13:00hot stream and a cold stream. The cold
1:13:03stream is directed into the the uh
1:13:07uh the respirator or ventilated helmet
1:13:10or the air vest and it can be used to
1:13:13cool the the worker. the hot stream is
1:13:16ejected and the the um the worker can
1:13:18actually can control the temperature. Um
1:13:21we used this in a um uh a task where
1:13:26some boiler makers were using uh air
1:13:29shielded welding and they weren't
1:13:31allowed to use um any kind of fan in the
1:13:34in the vessel because of the integrity
1:13:36of the weld. They were originally doing
1:13:3910 minutes of welding and then getting
1:13:41out and having a break. And this
1:13:43obviously wasn't very productive.
1:13:46Introducing the vortex tube with air
1:13:48vests and uh and ventilated uh helmets.
1:13:52They took that 10 minutes into a 2hour
1:13:55sec uh 2hour work period and to the
1:13:59point where the got to the uh the stage
1:14:02where the the boiler makers refused to
1:14:04get into the vessel unless they were
1:14:05allowed to use their their vortex tube
1:14:08and and ventilation vests. So quite an
1:14:10effective process. But as I said,
1:14:12limitations in that it it has to be used
1:14:15with a compressed airline.
1:14:17Other control options, don't forget your
1:14:19good old fan. Simple, effective. Just be
1:14:22cautious. Once the temperature gets
1:14:24around about 42° thereabouts, you are
1:14:28then increasing the heat load and fans
1:14:30lose their effectiveness and can
1:14:32actually be detrimental.
1:14:34This is a more high-tech approach. This
1:14:36is a chiller unit used for an asbestous
1:14:39enclosure. Pumps. It's a balanced
1:14:42chiller unit which pumps chilled air
1:14:44into the enclosure and keeps it at
1:14:46negative pressure. So, uh not affecting
1:14:49the integrity of the asbestous
1:14:51enclosure. We talked about work rest
1:14:54regimes.
1:14:56Uh this is face chilled vests
1:14:59work to some extent. They some guys love
1:15:02them, other guys hate them. U but use
1:15:05don't use ice vests. These are phase uh
1:15:08chilled vests. They freeze at around
1:15:11about 15 degrees, so they're not as a
1:15:14significant impact on the on the skin.
1:15:17And of course, this is the the vortex
1:15:20vest I I mentioned just before. So, it's
1:15:23a vortex tube with a chill vest.
1:15:28So, getting towards the end here, um,
1:15:30additional resources. These are what I
1:15:32call my two Bibles. If you really want
1:15:34to get into heat stress and want to
1:15:36understand them, uh Ken, you can't go
1:15:38past Ken Parson's book on heat and cold.
1:15:41It is a brilliant book. Uh I I have all
1:15:44three versions of this. I would never go
1:15:47anywhere without it. It's it's an
1:15:48excellent book. Uh and this one, Sport
1:15:51and Physical Activity in the Heat,
1:15:53Douglas Casser. It's made up of a number
1:15:55of chapters by different authors and
1:15:57again very very good.
1:16:00Additional resources, the ODA bulletin
1:16:03on heat stress has got some good
1:16:05resources there. There is a a website
1:16:09called global heat health which some has
1:16:13some good resources as well too. So some
1:16:16key points in summarizing I know I've
1:16:17gone well over time. Sorry about this.
1:16:20Um acknowledge the effects of a changing
1:16:23climate and rising global temperature on
1:16:25thermal risk assessments. It's happening
1:16:26whether we like it or not and we need to
1:16:28do something about it. The three-step
1:16:31protocol is a good approach. Use simple
1:16:34methods when at the start uh and involve
1:16:37the worker. Get them involved right at
1:16:39the the front line. And then go to
1:16:42advanced indices once it gets more
1:16:45complex. And don't [clears throat]
1:16:46forget the hierarchy controls. As O
1:16:49professionals and safety professionals,
1:16:52this is drummed into us when we are
1:16:54trained. Yet for some unknown reason,
1:16:56some of us tend to forget it. When it
1:16:57comes to heat stress, start at the top
1:17:00of the hierarchy controls, work your way
1:17:02down to admin and PPE, not the other way
1:17:07around.
1:17:08And use of indices and physiological
1:17:11monitors. Look, these are brilliant
1:17:13tools, but use them as guides only. You
1:17:16have to recognize that they are not
1:17:18all-encompassing
1:17:20uh and due to the, you know, the
1:17:22environmental task and individual
1:17:24variability. So great tools but know
1:17:28their limitations. So thanks for you for
1:17:32persisting out to as I said I know I've
1:17:35gone over time but uh thanks again for
1:17:37listening in.
1:17:39>> Thank you so much Ross. Um that's um
1:17:43absolutely excellent presentation. I
1:17:45think everyone's agreed. Um we still
1:17:48have about 250 people online and as you
1:17:51can see lots of accolades and um that
1:17:54was um that was absolutely fabulous. I
1:17:57think um as I'm thinking about it I I
1:18:00was thinking uh having you back for a a
1:18:03question and answer session would be
1:18:05something that we might consider. Um
1:18:08because there are a lot of questions in
1:18:09the chat. Um and uh I'm just uh maybe we
1:18:15could just take a few of them before we
1:18:17sort of sign off. I don't know how much
1:18:18time you have. I know it's late for you.
1:18:21>> No problems. I'm awake. [laughter]
1:18:24>> Well, thank you. Um so one of the
1:18:27questions was um could we share the
1:18:30chat? Uh so not the chat share the
1:18:33slides. Um,
1:18:36>> people are asking for that. I think
1:18:38people have found this extremely useful.
1:18:41>> Not a problem. If you send it out as a
1:18:43PDF, I'm happy to share it.
1:18:45>> Okay. And another question was uh will
1:18:47this be on the website? I think Maryanne
1:18:49has answered it. Um the the video will
1:18:51be on posted on the website. Um uh there
1:18:56were there was also a question about uh
1:18:59whether uh there are wearable monitor
1:19:02wearables to monitor heat and do you
1:19:04have any recommendations on those?
1:19:07>> Mhm. Okay. Yes, there are definitely
1:19:10lots of monitors now available. I'm very
1:19:13cautious in recommending any particular
1:19:17brand. Um, I can tell you some that I've
1:19:21used uh and the likes of uh the
1:19:24Equavital
1:19:26uh and I think uh core is it core temp I
1:19:30had on one of the slides. Um so they're
1:19:34the the sorts of things that I use but
1:19:35again I use them as guides. I use them
1:19:38to um uh help me get a better
1:19:42understanding of how the the people are
1:19:44coping. um you will I don't I would not
1:19:47be surprised if you you are inundated
1:19:50with people offering you um different
1:19:53types of wearable devices. I quite
1:19:56regularly get people saying, "Oh, here's
1:19:58a new device. Would you would you like
1:19:59to try it and recommend it?" Um
1:20:03get into the literature. I would suggest
1:20:05um
1:20:07look for peer-reviewed documentation
1:20:10that assesses some of these um wearables
1:20:13before you start spending lots of money.
1:20:16I already know of one company that has
1:20:18that is no longer um um selling its
1:20:22instrument. It's now gone off the market
1:20:24and a lot of people were caught out
1:20:26buying this particular instrument. So
1:20:27you need to be careful. Look at the
1:20:29peer-reviewed literature. Talk to your
1:20:31colleagues. see what they've used uh and
1:20:34before you start investing in in these
1:20:36tools.
1:20:38>> Okay. Um thanks. Uh there's also a
1:20:41question. Can one integrate ventilation
1:20:43with heat strain to estimate air changes
1:20:46per hour for a scenario?
1:20:49[sighs]
1:20:50>> Yes, you can. Uh this is starting to get
1:20:52a little bit out of my area. This is uh
1:20:54where the ventilation officers come into
1:20:57their own. And I've done some work with
1:20:59uh uh the likes of Rick Break um and
1:21:03they can estimate what they call air
1:21:05cooling power and which is very
1:21:07important particularly in underground
1:21:09mines. So yes, you can um I'm not really
1:21:14right up to speed with doing those
1:21:15calculations, but some of your
1:21:16ventilation officers in underground
1:21:19mines can tell you all about air cooling
1:21:21power and how to calculate air exchange
1:21:23rates. So definitely yes. And there is a
1:21:26question. Oh, sorry. Go ahead, Mary.
1:21:28>> No, that's right, Lisa. Oh,
1:21:31sorry. If you don't mind if I jump in
1:21:33for a couple of um sort of housekeeping.
1:21:36First, Ross, I also want to thank you so
1:21:38very much. I'm Marian Leitzky, by the
1:21:40way, from WHWB. I'm the Zoom host. Um
1:21:44Ross, tremendously appreciated
1:21:47presentation. Um I think everybody
1:21:49agrees with that. Uh I just want to live
1:21:51little give a word from your sponsor if
1:21:53[laughter] you don't to everybody. if
1:21:55you don't mind. Uh we are a nonprofit.
1:21:58Um we don't get we have provided this
1:22:01without charging but we do want
1:22:04donations. Um I put information about
1:22:07certificates in the chat and uh you know
1:22:11where else could you get a presentation
1:22:14of this depth and quality
1:22:16>> without charge and you get a certificate
1:22:18of attendance. Please think about that
1:22:21and please donate to us. Um I'll put the
1:22:24donation link in the chat. So thank you
1:22:26and [laughter]
1:22:28apologies for this but we have to keep
1:22:30the lights on. We have to keep the zoom
1:22:33[laughter] you know zoom costs money
1:22:34especially when we have this many
1:22:36participants. So please consider
1:22:38donating even a small amount. Okay. The
1:22:40other uh just pure housekeeping I've
1:22:43allowed unmuting. So if people if you
1:22:45have a few more minutes Ross and people
1:22:46want to ask a question verbally they
1:22:49could raise their hand and we will call
1:22:50on you and you can unmute. So sorry Lisa
1:22:53back.
1:22:53>> That's okay. Um while we're waiting if
1:22:56there are any uh verbal questions, one
1:22:58more question on uh conducting
1:23:00assessments in either agricultural or
1:23:02informal outdoor sectors. Any advice on
1:23:05that like like street vendors?
1:23:08>> Yeah. Well, definitely they're an area
1:23:11of concern and um uh I've actually seen
1:23:16fatalities occurring in the agricultural
1:23:18sector and which is very concerning. Um
1:23:21so yes, they're an area that we we need
1:23:23to to to consider. Um I think depending
1:23:28on where you are, it's not always uh
1:23:32the availability of of professionals to
1:23:35get out there and do the monitoring. So
1:23:38with the a lot of the agricultural
1:23:40sectors and um those sorts of areas, we
1:23:43need to work with the guys out in the
1:23:46field so that they they have that
1:23:48understanding of what the symptoms are,
1:23:51that understanding of what the potential
1:23:53controls are. Uh I was involved in an an
1:23:57unfortunate fatality a number of years
1:23:59ago in an in the agricultural field and
1:24:02the control was simply a shade cover.
1:24:07that's all they needed. Uh but you know,
1:24:09it was just overlooked. So sometimes the
1:24:12the controls in those sorts of um
1:24:15scenarios are very simple and very basic
1:24:18and the guys or the the ladies out there
1:24:20in the field can do that themselves if
1:24:23they have an understanding. So uh yeah,
1:24:26look, agriculture for me is a real
1:24:28concern when it comes to to heat stress.
1:24:30Agriculture and construction my two
1:24:32biggest areas of concern.
1:24:34>> Yeah. Yeah. Thank you.
1:24:38Um, are there any other questions before
1:24:40we sign off?
1:24:44Um, I think this was extremely
1:24:46informative. I I for one learned
1:24:48[laughter] learned a lot and I'm sure
1:24:50many others on this on this call did as
1:24:53well. So, we once again we really
1:24:56appreciate that that you're coming and
1:24:59and taking time uh in your evening to
1:25:02present um to this group. Um so much
1:25:05appreciated and uh thank you for sharing
1:25:07so generously sharing uh the video and
1:25:10the slides as well and your expertise.
1:25:13Um
1:25:14>> what a problem. Look for workplace
1:25:15health without borders. It's it's a
1:25:17brilliant organization. Always happy to
1:25:19support it and I hope others will too.
1:25:21>> Yeah thank you. We had over 280
1:25:24attendees today many from around the
1:25:26world. So much appreciated and I think
1:25:29uh
1:25:29>> definitely building uh expertise and uh
1:25:32sharing your skills and and building
1:25:34capacity around the world. So thank you

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