Protecting Field Workers in the Summertime Heat

Protecting Field Workers in the Summertime Heat

by Nicole Moyen

You can see the original article in T&D World, here.

Utilities’ and contractors’ field crews must often work in extreme heat during the summer months. Here is how to recognize symptoms of heat stress.

You’ve likely experienced a hot day working in the heat. You’re hot, thirsty, tired, and sweaty, and the work that you’re used to doing feels even harder. But why?

Your body wants to maintain a really tight temperature range: ~3-4°F or 2-3°C. But even increasing your body temperature by 1-2°F can have a big impact on your body’s physiological responses. Your body temperature goes up when you are accumulating heat faster than you can get rid of it.

You can accumulate heat from the environment, like when it’s really hot and humid outside, or when you’re exercising or working really hard in the heat. When you’re working or exercising, your muscles produce heat as a byproduct of the movements you’re doing. In response to this increase in heat production, we increase blood flow to the skin (to move heat from the body core to the skin) and start sweating to get rid of body heat.

However, if you’re producing heat faster than you can get rid of it, your body temperature will go up. As your body temperature gets higher, you will sweat more too in order to try to get rid of more heat. The hitch is that the sweat must be evaporating off of you to cool you down and reduce your core body temperature (i.e. dripping sweat doesn’t cool you down). As you’re sweating more, you’re losing more body water.

Your blood is made up of ~50% water, and so when you lose this water through sweating, your blood volume goes down. This is a problem because you need blood to go to the working muscles in your body for energy. Your blood carries oxygen, which is essential for your muscles to create the energy they need to keep working. This also means that you have less blood going to the skin to get rid of heat. As a result, your heart (which pumps the blood) has to work even harder to get the same amount of blood to your working muscles and to the skin. This means that your heart rate will be higher when working in the heat vs. working in a comfortable environment.

The loss of water (and therefore blood volume) through sweating is one of the reasons staying hydrated is so important. By replacing the fluids you’re losing through sweating, you can help your heart rate to stay lower during your work in the heat. In turn, this will allow you to work harder in the heat–simply by staying hydrated.

If you’re not staying hydrated on the job, not only will you have a higher heart rate, but you will feel more fatigued, and are more likely to be in a bad mood (frustrated, angry, etc), and you might also experience some “fogginess” in your thinking. So make sure that you’re taking frequent breaks, drinking plenty of fluids, avoiding alcohol, and eating healthy foods.

Most importantly, if you start to experience any of the signs and symptoms of heat injury or illness, be sure to stop working right away and take a break. These are early warning signs that your temperature is getting too high and you need to slow down and take a break. Remember that heat illness can lead to exertional heat stroke and even death. Take any signs and symptoms seriously.

Monitoring your heart rate with smart PPE or a chest strap can help you to know if you might be dehydrated, because your heart rate will be higher than normal for the same workload. Make sure that you are staying aware of how you’re feeling throughout the day, and have a buddy to check in with and talk to so that you can make sure you are both doing okay on really hot, humid days.

Drink plenty of fluids, stay cool, and pay attention to your body and any warning signs it might be giving you to stay safe in the heat.

Get Ready for a Safe Summer of Working in the Heat

Get Ready for a Safe Summer of Working in the Heat

by Nicole Moyen

You can see the original article in EHS Daily Advisor, here.

Heat is the invisible factor that affects your workforce. This summer and in the summers to come, temperatures are only projected to get hotter and more variable, so it’s increasingly important to know how to keep your employees safe while they work in the heat.

Aside from outfitting your workforce in smart personal protective equipment (PPE) that allows you to monitor them on a real-time, daily basis and keep them safe in extreme environments, there are several things you can do that are also effective.

Setting up the Worksite

Make sure there are easily accessible cooling stations for your team members that are less than a 5-minute walk from where they’re working. Here are some key considerations for creating your worksite cooling stations.

  • The cooling stations should have an ample supply of potable water that is kept cool and is near the workers’ rest stations.
  • These stations should also be under shade or in an air-conditioned area.
  • There should be a means to reach emergency services at each station in case a worker needs to undergo extreme and immediate cooling.
  • At least one chair or cot should be available at the cooling station in case a worker needs to sit or, if he or she is feeling light-headed, to lay down with his or her legs propped up on the chair to help return blood flow to the heart and brain.
  • There should be an emergency ice bath or cooling system available, such as an ice chest that contains cold compresses, kept within a short (i.e., less than 10 minutes) walk from all highly populated worksites. If the distance from worksites is greater, a mode of transportation should be provided for workers to get to these ice baths quickly if needed. Ice water baths are the number one way to save lives and prevent exertional heatstroke and death. You can also use a tarp (cradled around the individual) filled with ice and water in place of a tub.
  • Along with the ice bath, you will need to fill a chest of ice each day and make sure there is an ample supply of water present near the ice bath to quickly fill or refill the tub. If this is not possible, make sure cold compresses, an ice chest, and a cooler of water are placed near the highly populated worksites each day in case of emergency.

Educating Your Workforce

Make sure you educate yourself and your workers about the signs and symptoms of heat injury and illness, and encourage your workers to be honest when they’re not feeling well. Ensure they take breaks when needed to allow them to stay hydrated and at normal body temperatures throughout the workday. Educate your workers on the dangers of ignoring their signs and symptoms, as well; ignoring changes in their bodies could result in a serious heat injury or illness that will prevent them from working for days or even weeks.

If you don’t have individualized monitoring, you should employ work-rest schedules at your site, which are calculated based on workers’ clothing, the air temperature in the work environment, the humidity, sun exposure, and workload. You should check these work-rest tables each day to assess how long workers should be resting vs. working every hour. But be aware that these work-rest schedules are not specific to each individual, so there will be some individuals who need to rest earlier and some who can keep working despite the prescribed work schedules.

Workers should be made aware that these work-rest schedules are not “one-size-fits-all” and that they may need to stop sooner, or be able to work longer, than what’s prescribed. Many factors unique to each individual (e.g., age, sex, medications) will change how well a worker can tolerate the heat, which will affect how well he or she can work in the heat.

Let Workers Take Breaks When Needed

Letting your workers take breaks when needed—ideally resting for 10 to 15 minutes each hour when it’s very hot and humid—will help them keep their core body temperature lower and allow them to stay hydrated. This, in turn, allows them to work harder and longer while ensuring they stay alert and focused on the job.

If you push your workers too far, you can put them at risk of heat injuries and illnesses. Depending on which injuries or illnesses your workers obtain and the severity of the incident, they could be out of work for a day or up to several weeks. When in doubt, listen to your workers when they need to rest, and err on the side of caution by giving them a 10- to 15-minute break each hour to cool down. This will ensure your workforce stays safe and productive instead of risking long-term absences from work due to heat illness.

By making a commitment to stay informed and share your knowledge of heat safety with your workforce, your entire team will stay healthy, safe, and productive.



BUILDER contributor Nicole Moyen outlines the symptoms of two important heat-related injuries and how to detect and manage the risks on jobsites.

You can see the original article on Builder Online, here.

As we approach summer construction season, residential workers should re-educate themselves on heat-related injuries and illnesses that can happen to employees when working in warm conditions. Many workers and supervisors have experienced or witnessed changes in their physical abilities and limitations, caused by high-temperature environments. It’s important to understand what to look for and the differences between heat-related effects on the body, in order to detect and manage the health risks.

Heat Exhaustion
When your employees experience goosebumps or chills, light-headedness, nausea, and/or are feeling weak or more fatigued than usual, it’s likely they are experiencing heat exhaustion.

Heat exhaustion is typically the point where the cardiovascular system—the heart and blood vessels—can no longer support the work being done by the person. His/her heart rate will likely be higher when working in a hot (vs. a cool) environment. But heart rate can only increase so much, because the body only has a finite amount of blood that can be pumped by the heart to the working muscles for energy and to the skin to get rid of body heat. When this “maximum” point is reached in the cardiovascular system, a person feels symptoms of heat exhaustion: weakness, fatigue, faint/light-headedness, unusually hot skin, excessive sweat, and difficulty working or exercising.

Ideally, a worker has been trained to read the signals of their body when these symptoms occur, and knows the importance of stopping work to cool off and drink water to allow body temperature to come back down to normal. However, many workers may push through these feelings in order to stay productive and keep the job moving. This is the time when a supervisor must intervene to prevent heat-related injury or even a worker fatality.

An intervention means work stops immediately, and the worker is directed to a shady or air-conditioned shelter. Removing any extra clothing will allow the employee to cool down faster, and if the person is feeling dizzy or light-headed/faint you can elevate their feet to help return blood to the brain and heart. Use ice-cold towels placed on the body to cool it down, and encourage the worker to drink plenty of fluids, especially water, to boost hydration to a healthy level.

With these remedies, the worker should start to feel better within 10 to 15 minutes, and can safely return to work. However, it’s important to ease back into work gradually so as not to immediately disturb the care that’s just been given to the body. Make sure the affected employee slows down his/her work pace and takes extra breaks during the work day, even if they aren’t brought on by heat-related symptoms. This will help the person avoid another episode of heat exhaustion or other heat-related injuries.

Exertional Heat Stroke

Exertional heat stroke (EHS) is different from heat exhaustion. EHS should be considered a serious medical emergency. As such, if not treated properly, EHS can result in death. The good news is, if you understand EHS and take the proper prevention and monitoring steps, EHS is preventable.It is important to remember that heat exhaustion does not precede EHS. That means that heat exhaustion and EHS are two separate things: someone doesn’t necessarily need to experience heat exhaustion before getting EHS. Often, EHS can come about very suddenly, without any signs or symptoms. Exertional heat stroke is diagnosed when:

  • The worker’s core body temperature is greater than 104°F or 40°C. The only real way to differentiate between heat exhaustion and EHS is to measure core body temperature with a rectal or esophageal probe.
  • The worker’s central nervous system is experiencing dysfunction. When this happens, the person may be hallucinating, experiencing behavior changes such as aggressiveness, irritability, confusion, and/or irrational behavior. They may also feel weak or unable to continue working. The person may even collapse on the job or faint.
  • The worker may also experience vomiting, hot and sweaty skin, and fatigue, which are the symptoms of heat exhaustion, but the additional behavior changes noted above are the key clues that the person needs emergency cooling of the body, plus additional medical attention.

Preventing Heat Exhaustion and EHS
Now that you understand the two most common heat ailments that can happen on the job, it’s time to take stock of how you are preventing and managing them to keep your team safe from heat’s harm.

  • Encourage workers to use a buddy system while on the job. Buddies take on the responsibility of checking on specific co-workers’ well-being. Most teams already have informal buddy relationships that have formed, so it’s easiest to simply ask them to add this more formal “check up” to their existing collaboration. Buddies should talk to each other several times during the work day—not just while on break together. If one person notices something strange or out of character with the other, the observer should alert supervisors and immediately get the person to an emergency cooling station on-site.
  • Educate workers on the signs and symptoms of heat stress. Encourage them to pay attention to their own symptoms and what their body may be telling them. Let employees know it is dangerous to “push through” the situation by being “tough” under extreme circumstances. It’s not productive to the job. Heat stress actually slows the work pace and increases errors. In the end, a worker that passes out or must go to the hospital isn’t useful to himself/herself or the employer. Working safely is the ultimate goal, not speed or competition, or testing the limits of the human body.
  • Honor and recognize when a worker is vocal about symptoms. Take all comments about changes in the body seriously and let them take a break, find a cooler place, and drink water to recover before it’s too late.
  • Investigate additional equipment that can be used on site, such as smart personal protection equipment (PPE) that monitors and measures body indicators such as core body temperature, and sends a signal to both the worker and the supervisor that a safe heat threshold has been crossed, and a break and/or treatment are necessary.

Treating Heat Exhaustion and EHS
The symptoms detailed above are cues for both the worker and the supervisor to stop the individual from working, get them to shade or air conditioning to rest, and encourage them to drink fluids. It is also important to check on the person every five minutes to make sure they are recovering and feeling better. If, after 10 to 15 minutes, their symptoms have subsided, they may return to work. If not, continue treatment to eliminate the symptoms or seek professional medical attention for the worker if symptoms don’t subside.

If symptoms of EHS are present, immediately call on medical professionals by dialing 911. While waiting for EMTs to arrive, help the worker cool down as quickly as possible. Ideally, there will be ice bath supplies on-site to quickly cool the worker. Ice baths are the most effective way to treat EHS. If not, rotate cold compresses around the body to help cool the worker down. The most important thing to remember is to not leave the worker’s side while recovery begins and before help arrives.

Heat-related worker injuries are on the rise. If you haven’t paid close attention to the nuances of the signs and symptoms of heat injuries and illnesses, along with the ways to treat affected employees, you are putting everyone at risk. Be knowledgeable and proactive to keep your teams safe while getting the job done, especially during the high heat of the summer.



2020 is projected to be one of the hottest years on record,

which might be OK if you have air conditioning and work indoors.

But it could be hazardous if you work in the heat & have been sheltering-in-place. We tell you why.

At Kenzen, we believe that the hottest year on record combined with the COVID-19 pandemic will lead to even more heat-related deaths at worksites if employers don’t take the proper precautions.

Employers should not only be screening their workers for COVID-19 related symptoms, but be monitoring them for signs & symptoms of heat injuries & illnesses while at work. Why, you might ask?

7 Day Forecast in the 90s

With shelter-in-place orders across much of the globe, many people who work manual labor jobs are forced to stay home to avoid spreading COVID-19.

This means that many workers are likely spending most of their days in air-conditioned homes instead of working outside (as normal). This is problematic because research shows that those accustomed to air-conditioned homes are less tolerant of the heat.

Most heat-related deaths occur in the first few days of working on a job site in the heat. And one of the best ways to mitigate heat-related injuries & illnesses is to acclimatize to the heat. Many workers naturally acclimatize to the heat during the early summer (e.g. May & June) when temperatures start to increase, however, with shelter-in-place orders around the globe, this acclimatization period could be erased.

Instead, workers that have been sheltering-in-place during the early summer will likely be asked to go back to work in mid-July or August, in the dead-heat of the summer when they haven’t had a chance to acclimatize. On top of that, they will be asked to make up for “lost time” on the worksite. This means that not only will workers be asked to work harder when returning to the site, but they likely won’t be given the necessary time (~2 weeks) to acclimatize to the heat.

This is a recipe for disaster, that will likely lead to an increase in the number of heat-related deaths, injuries, and illnesses.

Oil field


  • Gradually ramp up their workloads each day & the amount of PPE that they’re wearing

  • Provide cooling stations & plenty of breaks in the first few days

  • Monitor your workers for signs & symptoms of heat-related injuries & illnesses during their first week back on the job site. The use of physiological monitoring of each individual can help to know when workers are getting too hot & need to take a break.

Let Kenzen help you in these crazy times. With our individualized physiological monitoring device, we make it so that you have one less thing to worry about and you can just focus on the task at hand.

Most importantly, we at Kenzen hope that you all stay safe, stay healthy, and stay cool.



  • Williams, Augusta A., et al. “Building Vulnerability in a Changing Climate: Indoor Temperature Exposures and Health Outcomes in Older Adults Living in Public Housing during an Extreme Heat Event in Cambridge, MA.” International journal of environmental research and public health 16.13 (2019): 2373.

  • Bain, Anthony R., and Ollie Jay. “Does summer in a humid continental climate elicit an acclimatization of human thermoregulatory responses?.” European journal of applied physiology 111.6 (2011): 1197-1205.




There are many factors that can increase your susceptibility for heat-related injuries and illnesses. Some of these factors you might have control over, while others you might not.



  • Age. After age 35 your body’s ability to dissipate heat (primarily through sweating) will decline. As a result, older adults tend to have higher core body temperatures than younger adults, when working at the same rate in the heat. This difference between older and younger individuals can be minimized with heat acclimatization and endurance training.

  • Genetics. Some people are able to acclimatize faster and tolerate the heat better than others; some of this appears to be attributable to genetic makeup. However, heat acclimatization can help level the playing field.

  • Diseases. Various skin disorders (e.g., psoriasis), cardiovascular diseases (e.g., hypertension), sweat gland disorders (e.g., Type I and Type II diabetes), and metabolic disorders can impair your body’s ability to effectively thermoregulate. This means that your core body temperature will be higher for the same workload, which puts you at increased risk for heat-related injuries & illnesses.


  • Drugs that affect your nervous system (e.g., antidepressants, sympathomimetics, anticholinergics, & antipsychotics). These drugs have been shown to impair your sweat gland function & increase your heat production, meaning that if you’re regularly taking these drugs, you’ll likely have a higher core body temperature for the same work rate than someone who is not taking these medications.

  • Antihistamines (e.g., allergy medications). These drugs can impair your sweat gland function making it harder for you to get rid of heat as readily, which can lead to an increased core body temperature.

  • Drugs that affect your cardiovascular system (e.g., beta blockers & calcium channel blockers). These drugs work to lower your heart rate. This is a problem when working in the heat because you need a higher heart rate to be able to pump blood to the skin (to get rid of heat) and the working muscles (for energy). As a result of the lower heart rate induced by these drugs, you might heat up faster and find it harder to maintain a high work rate in the heat.

  • Diuretics. These drugs make it difficult for you to stay hydrated, which means that in the heat, your body will be working extra hard to keep you cool. Remember that dehydration exacerbates the effects of heat stress.


  • Fitness. Making sure that you are healthy and staying fit can help you better handle the heat. A lot of the same adaptations you get with heat acclimatization (e.g., higher sweat rate and lower core body temperature) can also be obtained by doing endurance training in cool environments.

  • Acclimatization. Heat acclimatization is the best way to minimize your risk for heat-related injuries and illnesses. In general, it takes about 2 weeks to acclimatize to the heat; and once acclimatized, you need to be exposed to the heat at least every 3-4 days to maintain those adaptations. See here for how to do this.

  • Hydration. Since dehydration can exacerbate the effects of heat stress, it is important to stay hydrated. See our blog post on how to stay hydrated throughout the work day.

  • Listen to your body. If you start to experience any signs or symptoms of heat injuries or illnesses, take a break. Find shade, rest, and drink some water. Remove extra clothing if possible to help cool you off. Always listen to your body, and stop before it’s too late.

  • Sleep. More research is needed to determine the exact impacts of sleep on thermoregulation. However, if you know that you’re someone who doesn’t do well with minimal sleep, make sure you’re getting enough rest before spending a long day working in the heat.

  • Avoid drug use. Not only can recreational drugs (e.g., alcohol, ephedrine, cocaine, ecstasy) change your heart rate and blood pressure, they can also alter your body’s ability to get rid of heat (via increased blood flow to the skin and sweating). These drugs will quickly increase your risk for heat injury and illness, not to mention impair your abilities to successfully complete your job.

Now that you know all of the things that can harm and help you in the heat, it’s time to put that knowledge into action! Kenzen can help with our Heat Safety Training Program.



Pryor, J. Luke, Julien D. Périard, and Riana R. Pryor. “Predisposing Factors for Exertional Heat Illness.” Exertional Heat Illness. Springer, Cham, 2020. 29-57.