BATTLE OF THE SEXES: WHO DOES BETTER IN THE HEAT?

BATTLE OF THE SEXES: WHO DOES BETTER IN THE HEAT?

by | Mar 12, 2020 | Worksite Safety

Watch our first Kenzen video blog with VP of Research & Development, Nicole Moyen, as she explores the differences between how men & women handle working in the heat.

If men & women are working at the same relative work-rate, then men typically have a higher sweat rate than women (assuming men have a larger body surface area to mass ratio).

Remember: sweating is the main way that we get rid of body heat.

This higher sweat rate in men means that:

  • In hot-dry (low humidity) climates, men will likely be able to work for a longer period of time with a lower core temp than women, because they are better able to get rid of body heat through increased sweating.

  • In hot-humid climates, women will likely be to work for a longer period of time in the heat (with a lower core temp) because their lower sweat rate will keep them from losing body water (through sweating) that isn’t evaporating or cooling.

    • Men, on the other hand, due to their higher sweat rate will be losing a lot of body water through sweating, but it won’t be evaporating in the high humidity. So men will become dehydrated more quickly vs. women, and see a faster increase in core temperature.

This information is important to keep in mind if you have men and women on your workforce, so that you consider the humidity and sex when determining work/rest schedules for your employees that day.

For help setting up work/rest schedules at your site and heat safety training, check out our Heat Safety Training Program.

WHAT YOU’RE CONSUMING CAN HELP YOU OR HARM YOU IN THE HEAT.

WHAT YOU’RE CONSUMING CAN HELP YOU OR HARM YOU IN THE HEAT.

by | Mar 5, 2020 | Heat Injuries, Worksite Safety

BY JORDAN GLENN, PH.D. & NICOLE MOYEN, M.S.

There are several supplements that can help or harm you in the heat, and it might not be what you think…

crumpled cigarette packs

We have all seen the overwhelming wall of pills, powders, and tonics claiming to help cure every disease known to man. Some of these supplements even claim to help with working in a hot environment. But do they work?

The short answer is… maybe.

By definition, a supplement is exactly that. Not a replacement or a stand alone food item, but a supplement to your day to day nutrition. And as is the same with most supplements, they are generally only useful when we are lacking in our normal nutritional health.

TWO SUPPLEMENTS THAT MIGHT HELP YOU IN THE HEAT:

Creatine:

Creatine is one of the most popular nutritional supplements in the world. While most people tend to take creatine to increase muscle size with weightlifting, there is major concern that creatine can lead to muscle cramping, primarily from dehydration.

It was once thought that because creatine causes more water to be held in the muscle cells, it would lead to dehydration.

However, research has shown us that these fears are not only unnecessary, but reversed! Scientists now believe that creatine may actually improve our tolerance to the heat. It turns out that the extra water held in the muscle cells may actually enhance our body’s ability to deal with heat stress.

Take action: For optimal results, start with 20 g/day for one week, followed by a maintenance dose of 5 g/day thereafter. Unlike Vitamin C, it is hard to get enough creatine naturally from your diet, so supplementing with creatine is the best way to increase levels.

Vitamin C:

Although research is conflicted, it has generally been shown that taking a Vitamin C supplement can lower core body temperature during the first few days of heat acclimatization, thus minimizing the risk of heat-related injuries and illnesses.

Moreover, although the amount of vitamins lost through sweating is minimal, research indicates that for individuals who have a diet lower in Vitamin C and are consistently working in the heat (and sweating a lot), can benefit from taking a daily dose of Vitamin C to help replenish stores that are lost through sweating.

Take action: For optimal results, take 250 mg/day, and not more than this amount because it can compromise the absorption of vitamin B12.

ONE THING THAT DOESN’T HELP OR HINDER YOU IN THE HEAT

Caffeine:

While caffeine tends to be a bit confusing as to its effects on overall health, research has shown that caffeine does not seem to affect performance in the heat or increase the risk of heat illness. And if you are a regular coffee or tea drinker, research shows that regular consumption of coffee or tea will not dehydrate you. So while caffeine may not help you beat the heat, it won’t hurt you either.

THINGS THAT CAN HARM YOU IN THE HEAT

Nicotine:

Consistent nicotine use (in the form of tobacco, cigarettes, etc) can impair your ability to get rid of body heat because nicotine use alters your sweating and skin blood flow mechanisms, making you more susceptible to heat-related injuries and illnesses. Even short-term nicotine use in the heat can be dangerous because nicotine is a stimulant, which leads to increased heart rate and blood pressure, meaning that your cardiovascular strain will not only be higher from the heat, but also from the nicotine. It’s best to avoid nicotine-related products altogether.

Alcohol: 

While alcohol can lead to vasodilation, which in theory, would help to dissipate heat, the slight benefit does not outweigh the harm. Alcoholic drinks (>4% ABV) lead to increased urination (they act as a diuretic), which can dehydrate you. This means that if you’re drinking alcohol after a long day of working in the heat, you probably will not replenish the body water you lost that day through sweating, and so you will start the next work day dehydrated.

This of course is a problem because dehydration exacerbates the effects of heat stress on the body by reducing sweat rate and skin blood flow— the two key mechanisms to get rid of body heat— and also increases the cardiovascular strain on your body. This means that you won’t be able to work as hard or be as productive at work when dehydrated, and you are also more susceptible to heat-related injuries and illnesses.

Moral of the story: be aware of the things you’re consuming that might help you, but can also harm you in the heat. 

AND REMEMBER THAT HEAT ILLNESSES ARE 100% PREVENTABLE!

For more information on emergency cooling procedures, or to have Kenzen make your worksite heat-safe, see our Heat Safety Training Program.

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REFERENCES

  1. https://doi.org/10.1007/s00726-016-2237-9
  2. https://www.ncbi.nlm.nih.gov/books/NBK236216/
  3. Pryor, J. L., Périard, J. D., & Pryor, R. R. (2020). Predisposing Factors for Exertional Heat Illness. In Exertional Heat Illness (pp. 29-57). Springer, Cham.
3 THINGS YOU NEED TO KNOW ABOUT WORK/REST SCHEDULES

3 THINGS YOU NEED TO KNOW ABOUT WORK/REST SCHEDULES

by | Feb 26, 2020 | Heat Injuries, Worksite Safety

WORK/REST SCHEDULES CAN HELP PREVENT HEAT INJURY & ILLNESS ON HOT DAYS.

BUT THERE ARE 3 IMPORTANT THINGS YOU NEED TO KNOW BEFORE ADMINISTERING THESE SCHEDULES TO YOUR WORKFORCE.

Construction worksite

  1. These work/rest schedules are not “one size fits all.” What does this mean? Well that a work/rest schedule of 30 minutes working and 30 minutes resting on a really hot day is not going to prevent heat injury or illness in ALL people. The research backing these work/rest schedules has largely been based upon young, healthy men, which means that other populations (older individuals, women, diseased populations) might need very different work/rest schedules.

    “…existing guidelines adopted and recommended for use by government agencies worldwide (e.g., WHO, CDC, others) to protect the public and workers also assumes a “one size fits all” approach to protect human health. These guidelines generally prescribe protective measures (e.g., heat advisories, exposure limits) using models defined by the assessment of heat strain in young and or relatively healthy adults. They fail to consider key factors such as sex, age, health status, and other factors, which can markedly alter a person’s tolerance to heat, thereby leaving a large segment of the population under-protected… “ (1)

  2. Work/rest schedules vary depending on the organization or governing body that developed them. For example, OSHA & the US Army use a similar work/rest schedule, while the EPA & ISO standards have slightly different recommendations. That being said, it’s important to understand how these recommendations vary, but more importantly, what factors they consider in giving the work/rest schedules (e.g., wet bulb globe temperature-WBGT, temperature, humidity, clothing, sun exposure, wind speed, etc).
  3. One of the biggest problems with work/rest schedules (especially those using WBGT), is that they severely underestimate the heat strain experienced by workers when the evaporative capacity (of sweat) is limited—like in very humid environments or under heavy clothing layers— this means that more workers will be susceptible to heat injury & illness when using WBGT-based work/rest schedules under these conditions. (2)

Table of WBGT Categories

Example of U.S. Army work/rest schedules (3)

SO IN ADDITION TO IMPLEMENTING WORK/REST SCHEDULES,

MAKE SURE YOU’RE ALSO DOING THE FOLLOWING 5 THINGS TO PROTECT YOUR WORKERS:

  1. First and foremost, you can get your workers set up with smart PPE, like the Kenzen patch, that will monitor workers’ physiological data real-time and alert you (and the worker) when their core temperature is reaching unsafe levels, so that they can take a break. This is completely individualized, which solves the problem of work/rest schedules not protecting all populations.
  2. During the rest periods, let your workers actually rest. DO NOT assign any other work tasks while they’re resting- your workers need to cool down, and if they continue to work, their core temperature will keep going up. (3)
  3. Keep checking the weather (WBGT, temperature, and humidity) throughout the day— we recommend every 2 hours— and update the work/rest schedules accordingly if the criteria change.
  4. During rest breaks: provide workers with potable water and shade or air conditioning, and allow them to remove any extra clothing that might restricting evaporative heat loss (i.e., that keeps the sweat from evaporating off of their skin). (5)
  5. If you don’t have a way of monitoring each worker’s individual physiology, then make sure you are attentive to each individual and whether they might be presenting any signs or symptoms of heat injury or illness. Let the individual stop working and rest if they need to (even if the working time limit hasn’t yet been reached). (4,5)

    Lastly, remember: these work/rest schedules were created for young, healthy men, so you will need to pay special attention to how older adults, women, and those with diseases are responding to these schedules on a hot day because they might need a completely different program to stay safe in the heat.

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REFERENCES:

  1. Kenny, G.P., Notley, S.R., Flouris, A.D. and Grundstein, A., 2020. Climate Change and Heat Exposure: Impact on Health in Occupational and General Populations. In Exertional Heat Illness (pp. 225-261). Springer, Cham.
  2. Budd, G.M., 2008. Wet-bulb globe temperature (WBGT)—its history and its limitations. Journal of Science and Medicine in Sport, 11(1), pp.20-32.
  3. Regulation, T.R.A.D.O.C., 2016. 350-29. Prevention of heat and cold casualties. Fort Eustis, VA: US Army Training and Doctrine Command, Publication TRADOC Regulation, pp.350-29.
  4. Coco, A., Jacklitsch, B., Williams, J., Kim, J.H., Musolin, K. and Turner, N., 2016. Criteria for a recommended standard: occupational exposure to heat and hot environments. control Ccfd, editor.
  5. https://www.osha.gov/heat/
DOES POURING WATER ON YOUR HEAD ACTUALLY COOL YOU DOWN?

DOES POURING WATER ON YOUR HEAD ACTUALLY COOL YOU DOWN?

by | Feb 6, 2020 | Heat Injuries

We’ve probably all been there: sweating it out in the heat, wishing we were in a cool lake or pool, and so we reach for that water bottle and pour the water on our head for some relief.

But does this actually cool you off or is this relief just temporary?

underwater

The answer: it depends on your conditions.

In a hot-dry environment (low humidity):

  • Pouring water over your head can cool you off and lower your core body temperature, but the caveat to this is that you have to be in a place where the water you poured on your body can evaporate off of your skin and get rid of heat (remember, only sweat that evaporates off of your skin actually cools you off).
  • A good breeze is also important to help wick the water off of your skin to cool you down.
    And as you’ve probably guessed, you’d also need to be wearing minimal clothing— like shorts & a t-shirt— as heavy clothing, like PPE, would just trap the water you poured on your body.

strong>In a hot-wet environment (high humidity):

  • If your sweat is already dripping off of you and it’s really humid outside then pouring water over your head might make you feel better, but won’t help you cool down.
  • Research has shown that pouring water over your head can make you feel cooler by reducing your skin temperatures and also reduce your perceived exertion (how hard you feel like you’re working) in the heat. However, it won’t improve your performance.

So, what’s the verdict on pouring water over your head?

Unless you’re wearing light clothing and working in a hot-dry environment where the water can evaporate off of your skin, it won’t help to cool you off. That being said, if it makes you feel better to pour cold water over your head and helps you get through the work day, it won’t hurt you, so go for it- just remember to keep an eye on the signs & symptoms of heat illness.

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REFERENCES:
Munoz, C. X., et al. “Effects of oral rehydration and external cooling on physiology, perception, and performance in hot, dry climates.” Scandinavian journal of medicine & science in sports 22.6 (2012): e115-e124.
Morris, Nathan B., and Ollie Jay. “To drink or to pour: How should athletes use water to cool themselves?.” (2016): 191-194.

WHAT IS YOUR SWEAT RATE & WHY DOES IT MATTER?

WHAT IS YOUR SWEAT RATE & WHY DOES IT MATTER?

by | Jan 23, 2020 | Heat Injuries

Calculating your sweat rate is the best way to figure out how much water you need to be drinking when working or exercising in the heat.

You can use our sweat rate calculator (see below) to figure out your average sweat rate, and how much water you should drink back after your exercise bout or work day.

WHAT YOU NEED TO DO TO GET AN ACCURATE SWEAT RATE CALCULATION:

  1. Pick an activity (ideally during your typical workday) that is 30-60 minutes long, where you are usually sweating. Note that you will need to weigh yourself (nude) before and after the activity, so if this is not possible at work, then go for a run at home or the gym, or do some sort of aerobic (endurance) activity that gets your heart rate up & causes you to sweat (e.g., elliptical, cycling, etc).
  2. Weigh yourself (nude) before exercise and/or work. Write down this number. Go do your activity – and be sure to keep track of the time (be as precise as possible). Note: During this exercise period, you should not use the restroom or drink any fluids. Immediately after you’re done, take your clothes off & wipe off any dripping sweat from your body.
  3. Weigh yourself (nude) again. Write down this number. Enter your two body weights & your exercise/work duration in the calculator below to get your sweat rate & how much water you should drink back!

Sweat Rate Calculator

 

Note that the amount of water to drink back is the amount specific to the activity you did (and that amount of time). If it’s really hot outside, your sweat rate might be even higher, and then you’ll need to drink even more water.

**Remember that you can’t just chug all of that water at once because your body can only absorb it so fast.. as a general rule of thumb, your body can only absorb ~1 cup (8 oz.) of water every 15 minutes, so try to divide up your fluids (over the hour) based on that rule.

For more information, check out our blog on staying hydrated during the workday.

THIS IS A GOOD PLACE TO START, BUT FOR MORE CUSTOMIZED HYDRATION PLANS & RECOMMENDATIONS SPECIFIC TO YOUR SITE, WORK ACTIVITIES, AND CLOTHING, CHECK OUT KENZEN’S HEAT SAFETY PROGRAM– WE’RE HERE TO HELP.