Assistance Requested - Hot Weather Safety Guidelines

Started by Ned, July 26, 2015, 10:20:08 PM

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Ned

For some time, it has been apparent that the current hot weather guidelines in CAPP 52-18 are not useful for the great majority of cadet activities.  Our current guidelines are based on the military's WBGT / "Flag System" system, more completely described in Air Force PAM 48-151. 

The problem, of course, is that the typical unit does not have access to WBGT readings, and WBGT readings are difficult to calculate without the appropriate instrumentation.  Bottom line, requiring the use of the WBGT system without a practical method of compliance may be worse than having no guidelines at all.

Expanding a bit, practically speaking WBGT are pretty much only available on military bases, and even on military bases the information is often unavailable.  Just two examples - I organized a 5k run for the CAWG cadet conference held on a National Guard facility, but the Range Control folks were not in the office that weekend, and no other source of information was available.  Similarly, I'm currently at Maxwell working COS, and the base ops folks go off duty at 1600.  We play volleyball nightly at 1830, and while we have WBGT data from 1600, it is not updated later in the day and conditions change between 1600 and 1830.

I can only imagine what it is like for a typical squadron trying to conduct a summer activity without access to WBGT information.

So, I want to revise our guidelines and include some hot weather advice based on easily accessible data and written in a way that will provide practical guidance to CP officers in conducting ORM for the troops.

We could consider Heat Index (HI), but it does not consider some factors that WBGT does, like radiation.  I also cannot find much evidence-based guidance for HI related to activity levels.

The Weather Channel folks and some others use proprietary "feels like" calculations, but again, I can't find much authoritative guidance that would allow me to confidently build recommendations for CP officers.

So, I'd like to start a discussion about what we should use to replace the current WBGT.  As a rule of thumb, we should be use easily accessible data, and provide some authoritative and evidence-based guidance that is easily understood and implemented by the average commander / CP officer.

Thoughts?

Ned Lee
National Cadet Programs Manager

LSThiker

Ned,

I agree that WBGT is outdated and difficult to ascertain.  Some time ago (about 3 years ago), I had sent up a proposal to eliminate the use of WBGT indices and adopt the use of heat index.  Obviously it went no where and unfortunately I have sense lost that draft.  When I wrote the proposal, I used information essentially found in the attached document.

In regards to "solar radiation", the easiest thing to do is to add 15 degrees to the heat index when working in direct sunlight. 

It must be stated that like any tool, heat index and heat stress index has its limitations.  There is no one best method as there are too many variables in determining the heat load on a person's body.

Thanks,

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Brit_in_CAP

If I might add a slight extension to the scope of your discussion, it would be useful if there could be combined guidance for both hot and cold weather.

Our unit meets at a FBO and we can access, via a display screen, the FAA live weather data for the FBO.  In the winter, we use that combined with the official wind chill table to determine how long cadets can be outside for activities such as drill and, for example, DDR training but winter PT can be hard to assess.

We can access the same data in the summer, obviously, but we've no real means of processing that into a meaningful guide.  That being said, are the (relatively) cheap items from hardware stores of any use in determining the components for the calculations?

AirAux

Ned, thank you for trying to address this issue.  I guess since we are playing military we can throw common sense out the window.  We recently changed required tee shirts to be black, one of the hottest colors available.  Here in Georgia with our lovely scorching heat and oft times high humidity, the cadets at encampment are sweltering.  The thought of the day being that black tee shirts under BDU's with the sleeves rolled down are the ideal way to protect from sun and heat.  Really, and I am a doctor so don't let them say this is the best way to go.  Remember they said we shouldn't eat butter or bacon 25 years ago and recently found out they are wrong.  It is just a matter of time until we have a cadet or overweight senior member in blue BDU's down with heat stroke or dead.  There is no good reason civilian cadets or senior members should have to go through this.  Some CO's will not let the cadets roll up their sleeves or take off their blouses because they aren't following military protocol.  Well, guess what, we are NOT military!  Good luck Sir and I hope for the best, but expect nothing due to the nature of our organization.

Brit_in_CAP

Did a little lunch break surfing.

There are commercial "meters" available but they are priced beyond the range where most units could afford one.  The cheapest I found was a stopwatch that also calculated the HI, priced at $35.  I offer no recommendation, merely stating the price.

The NWS offers a chart of their website:

http://www.nws.noaa.gov/om/heat/heat_index.shtml

They also offer a calculator and the method they use.  Could we, perhaps, recommend that NWS website for most activities and provide a "how to" guide to calculate the outcome, either using a spreadsheet of a calculator?  We're not always within range of the WWW, after all!

We use the NWS wind-chill chart in the winter; could these two sources be combined to offer guidance for activities across the year?  I printed and laminated the wind-chill chart - we could perhaps do that for the two charts and attach a table guiding activity organizers as to the appropriate levels of activity.  Most units can obtain a basic thermometer for the actual air temp, and there are sensibly priced and appropriately accurate humidity gauges available from DIY stores, often combined with a thermometer.  I saw one costing around $10, for example.

End of my 10-cents contribution.

LSThiker

#5
Quote from: AirAux on July 27, 2015, 04:05:41 PM
We recently changed required tee shirts to be black, one of the hottest colors available.

That statement is factually incorrect.  Black is not the hottest color.  In fact, there is no real method for measuring "hot" as it is not quantifiable.  Hot is a qualitative.  Black has the highest heat transfer.

QuoteReally, and I am a doctor so don't let them say this is the best way to go

So you provide no real evidence but say "I am a doctor".  This is known as Appeal to Authority.

QuoteRemember they said we shouldn't eat butter or bacon 25 years ago and recently found out they are wrong

Science is an ever evolving field.  In fact, it was only recently (~100 years) that the medical field was saying wear white in the summer and black in the winter.  We found that is not really true either. 


QuoteThe thought of the day being that black tee shirts under BDU's with the sleeves rolled down are the ideal way to protect from sun and heat.

It really is more complicated than that.  There are numerous factors that contribute to heat stress from clothing.  There are at least six factors that contribute to insulation (heat or cooling) of clothing.  These include:

1)  Wind speed (increased speed disturbs zones of insulation)
2)  Body movements (movement causes air flow around skin)
3)  Chimney effect (loosely having clothing helps to ventilate trapped air)
4)  Bellows effect (movement increases ventilation to areas with trapped heat)
5)  Water vapor transfer (passage of water through clothing allowing evaporative cooling)
6)  Permeation efficience factor (wicking actions that aids in evaporative cooling).

As far as wearing sleeves down, that is actually important in reducing heat load.  Clothing has been found to decrease heat load caused by radiant heat transfer (Pascoe et al., 1994).  In regards to black vs white, well that gets complicated.  Strictly speaking, wearing black does increase radiative heat gain and does contribute to the heat load (Nielsen, 1990).  However, most studies that demonstrate the heat gain fail to report on the heat loss due to the black clothing.  Remember, while black objects gain heat faster than white objects, black objects also release heat faster than white objects.  In addition, white allows greater penetration of short-wve radiation when compared to black.  It was found that white pigeons actually had more heat flow inward when compared to dark colored pigeons when exposed to solar radiation with a wind speed of 3ms-1 (Walsberg et al, 1978). 

Regardless, this is where it gets complicated.  When speaking of black fabric vs white fabric, you must take into account all of the above factors.  This was done in the 1980s with a Nature paper.  Shkolnik et al wanted to know why Bedouins wear black robes while working in high temperature environments.  A group of people that, had black been terrible to wear in the heat of the desert, they would have abandoned it in favor of white fabric.  However, over the centuries, Bedouins, along with many numerous desert dwelling cultures, continue to wear black.  Granted, there are plenty of groups that also wear white.  What Shkolnik et al had found was that regardless of whether they wore white or black, the amount of heat gain was essentially the same.  While the black absorbed more, it quickly lost it when compared to white robes.  In addition, they noted exactly as above.  The type of fabric, how they wore it, what it covered all worked in their favor. 

A few factors that are not taken into are acclimatization and hydration of the person along with proper fitness and other general health issues.

It has been found in numerous studies that going S-N or semi-nude is actually better than wearing either cotton or synthetic fabrics in regards to heat load.

TheSkyHornet

Quote from: LSThiker on July 27, 2015, 07:17:39 PM
Chimney effect (loosely having clothing helps to ventilate trapped air)

Burqas for all!

Slim

I've got an app on my smartphone that was created by the folks at OSHA that will calculate heat index.  Just enter the temperature and relative humidity, and it will give you the heat index, risk level, and precautions to take based on those levels. 

WBGT? No.  Perfect? no.  However, if I'm running an activity or something, and the heat index level tells me people should be drinking four cups of water an hour, and on a 20 minute/10 minute work/rest cycle, that's what I'm going to do. 


Slim

Brit_in_CAP

Quote from: Slim on July 28, 2015, 06:50:28 AM
I've got an app on my smartphone that was created by the folks at OSHA that will calculate heat index.  Just enter the temperature and relative humidity, and it will give you the heat index, risk level, and precautions to take based on those levels. 

WBGT? No.  Perfect? no.  However, if I'm running an activity or something, and the heat index level tells me people should be drinking four cups of water an hour, and on a 20 minute/10 minute work/rest cycle, that's what I'm going to do.
Neat; what's the app called?  I tried to find one such yesterday and couldn't.  As you say, it might not be WBGT or even perfect but it's a start.  To the original point, I think Ned was looking for something that could be used widely across CAP, and this might fit the bill.   I'm intrigued enough to talk to my OSHA-qualified colleagues at work and see if they have any ideas, something I should have though of before.

Spam

I think you might be thinking of this OSHA tool, available for both platforms:

Video demo:
https://www.youtube.com/watch?v=3M_mCEf3UaY

Android version:
https://play.google.com/store/apps/details?id=com.erg.heatindex&hl=en

iPad/iPhone version:
https://itunes.apple.com/us/app/osha-heat-safety-tool/id469229784?mt=8


I was at the Georgia encampment late last week to help execute our HC-130J rides, and yeah, I had cadet officers approach me, furious at having to wait an hour at 4PM in the heat with known heat casualties "propped up" (*their words) for a group photo because that's supposedly the only time when the base photographer was available. The cadets railed about how they "hear all this crap about ORM and safety" and "how we're supposed to stop risky events" and yet were ordered to drag their casualties out of medical for the photo. Having an app like this could help arm ALL of our people in making a time out call, and skipping events like this, without relying on he said-she said arguing about WBGT data which few understand well. 

Planning and scheduling large dynamic events is hard; factoring in heat and cold countermeasures needs to be user-friendly to work well. Thanks Ned!


V/R,
Spam



Brit_in_CAP

Quote from: Spam on July 29, 2015, 04:03:22 AM
I think you might be thinking of this OSHA tool, available for both platforms:

Video demo:
https://www.youtube.com/watch?v=3M_mCEf3UaY

Android version:
https://play.google.com/store/apps/details?id=com.erg.heatindex&hl=en

iPad/iPhone version:
https://itunes.apple.com/us/app/osha-heat-safety-tool/id469229784?mt=8


I was at the Georgia encampment late last week to help execute our HC-130J rides, and yeah, I had cadet officers approach me, furious at having to wait an hour at 4PM in the heat with known heat casualties "propped up" (*their words) for a group photo because that's supposedly the only time when the base photographer was available. The cadets railed about how they "hear all this crap about ORM and safety" and "how we're supposed to stop risky events" and yet were ordered to drag their casualties out of medical for the photo. Having an app like this could help arm ALL of our people in making a time out call, and skipping events like this, without relying on he said-she said arguing about WBGT data which few understand well. 

Planning and scheduling large dynamic events is hard; factoring in heat and cold countermeasures needs to be user-friendly to work well. Thanks Ned!


V/R,
Spam
:clap: :clap:

Tim Day

Quote from: LSThiker on July 27, 2015, 07:17:39 PM

A few factors that are not taken into are acclimatization and hydration of the person along with proper fitness and other general health issues.

It has been found in numerous studies that going S-N or semi-nude is actually better than wearing either cotton or synthetic fabrics in regards to heat load.

So... drink water and reduce down to PT gear?
Tim Day
Lt Col CAP
Prince William Composite Squadron Commander

LSThiker

Quote from: Tim Day on July 31, 2015, 05:52:08 PM
Quote from: LSThiker on July 27, 2015, 07:17:39 PM

A few factors that are not taken into are acclimatization and hydration of the person along with proper fitness and other general health issues.

It has been found in numerous studies that going S-N or semi-nude is actually better than wearing either cotton or synthetic fabrics in regards to heat load.

So... drink water and reduce down to PT gear?

No of course not.  Drink water and wear a speedo or bikini because it is only a matter of time.....

NIN

Quote from: LSThiker on July 31, 2015, 07:34:27 PM
No of course not.  Drink water and wear a speedo or bikini because it is only a matter of time.....

"I'm getting some input here that I'm reading as relatively hostile."
Darin Ninness, Col, CAP
I have no responsibilities whatsoever
I like to have Difficult Adult Conversations™
The contents of this post are Copyright © 2007-2024 by NIN. All rights are reserved. Specific permission is given to quote this post here on CAP-Talk only.

LSThiker

Quote from: NIN on July 31, 2015, 08:04:03 PM
Quote from: LSThiker on July 31, 2015, 07:34:27 PM
No of course not.  Drink water and wear a speedo or bikini because it is only a matter of time.....

"I'm getting some input here that I'm reading as relatively hostile."

Go to hell Geek

NIN

Darin Ninness, Col, CAP
I have no responsibilities whatsoever
I like to have Difficult Adult Conversations™
The contents of this post are Copyright © 2007-2024 by NIN. All rights are reserved. Specific permission is given to quote this post here on CAP-Talk only.

A.Member

Quote from: LSThiker on July 31, 2015, 08:22:51 PM
Quote from: NIN on July 31, 2015, 08:04:03 PM
Quote from: LSThiker on July 31, 2015, 07:34:27 PM
No of course not.  Drink water and wear a speedo or bikini because it is only a matter of time.....

"I'm getting some input here that I'm reading as relatively hostile."

Go to hell Geek
Does that directive come with a heat index warning?
"For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return."

A.Member

If you have a hot weather guidelines, will there also be cold weather guidelines?

My $.02, this varies significantly by region to be regulated.  People acclimate differently to the areas they live in.  This is something that should be addressed in pre-activity ORM with guidance geared more towards ensuring proper supervision, hydration, etc appropriate to the activity.  Absolutes can be problematic.
"For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return."

NC Hokie

Quote from: A.Member on July 31, 2015, 09:05:44 PM
My $.02, this varies significantly by region to be regulated.  People acclimate differently to the areas they live in.  This is something that should be addressed in pre-activity ORM with guidance geared more towards ensuring proper supervision, hydration, etc appropriate to the activity.  Absolutes can be problematic.

Agreed.  For example, one of my cadets just returned from NBB making fun of all the people complaining abut the heat in Oshkosh.  Temperatures in the 80's are indeed hot, but that's a cool respite from the summertime climate in eastern North Carolina, which was ten degrees hotter and much more humid during those same two weeks.
NC Hokie, Lt Col, CAP

Graduated Squadron Commander
All Around Good Guy

LSThiker

Quote from: A.Member on July 31, 2015, 08:57:16 PM
Quote from: LSThiker on July 31, 2015, 08:22:51 PM
Quote from: NIN on July 31, 2015, 08:04:03 PM
Quote from: LSThiker on July 31, 2015, 07:34:27 PM
No of course not.  Drink water and wear a speedo or bikini because it is only a matter of time.....

"I'm getting some input here that I'm reading as relatively hostile."

Go to hell Geek
Does that directive come with a heat index warning?

"withstand a temperature of over 1000 degrees"

Quote from: NC Hokie on July 31, 2015, 11:28:09 PM
Quote from: A.Member on July 31, 2015, 09:05:44 PM
My $.02, this varies significantly by region to be regulated.  People acclimate differently to the areas they live in.  This is something that should be addressed in pre-activity ORM with guidance geared more towards ensuring proper supervision, hydration, etc appropriate to the activity.  Absolutes can be problematic.

Agreed.  For example, one of my cadets just returned from NBB making fun of all the people complaining abut the heat in Oshkosh.  Temperatures in the 80's are indeed hot, but that's a cool respite from the summertime climate in eastern North Carolina, which was ten degrees hotter and much more humid during those same two weeks.

It really does.  A lot of the hot weather work/rest cycles are really a guideline in setting up ORM.  They are not absolutes.  Obviously, a squadron in the South that has temperatures of 90+ during 7pm nearly everyday is different than a squadron in Maine that is having a heat wave.  While both may be at 90+F, the people are obviously differently adjusted.

I can relate to the NBB jokes.  When I moved here, I was dying with the high humidity summer.  I had no problem with having temperatures over 100F, but the 70% humidity at that temp was a killer.  However, when winter rolled around and temperatures dropped to 40F, I was walking around in short sleeves without a jacket while the residents were wearing thick winter jackets.  Now, I am out running when it is 95F and 60% humidity and it does not even bother me.  When winter rolls around, I now require a light thin jacket. 

If I were a commander living here, I would not necessarily jump to black flag hysteria even though the temperature (without having to read a WBGT) rates as much.  That is not to say that I would be cautious, but I would not necessarily freak out.  If I were to move back where temperatures barely got over the 85F mark, I would very much jump on a black flag if temperatures were 95F.