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Safety Management Insights

Heat Stress Prevention: Top 5 Tips to Stay Cool At Work

Posted by Chris Brockmann on Sep 7, 2020 12:26:23 PM

heat stress prevention

Heat stress...
One moment your guy is sweating profusely, the next he hits the floor. (Heatstroke.) Workers tend to underestimate heat - not just its physical but also its cognitive effects. 
That's why it becomes imperative for safety professionals like you to understand how heat contributes to unsafe work conditions so you can take proper precautions and prepare your guys. 
(Want to manage EHS more easily? Watch this.)



Heat stress (also sometimes referred to as "heat exhaustion") is a condition caused by the body’s exposure to extreme temperatures.

Heat stress occurs when the body is no longer able to maintain a healthy body temperature in a hot environment. If the surrounding temperature is higher than your body's temperature of 98.6ºF, your body will absorb heat instead of getting rid of it. This is where the problems begin.



  1.  Water depletion - Common symptoms: excessive thirst, headache, weakness, fainting
  2.  Salt depletion  - Common symptoms: cramps, headache, nausea, dizziness
heat stress prevention

This is useful to know so workers can take appropriate precautionary measures and quickly remedy issues (cramps, dizziness, etc.) when signs & symptoms arise.

(We'll talk more about symptoms and treatments for heat stress in just a moment.)




Even death.

Know the "cost". Now, even though heat stress isn't as severe as a full-blown heatstroke, it can quickly progress to a heatstroke. Heatstrokes can damage the brain, organs, and, in some cases, even turn fatal. So, don't take it lightly!

Quick Tip For Safety Managers: Communicate the "true cost of ignoring signs & symptoms". This is crucial when it comes to heat stress prevention and keeping workers safe since ego and complacency are often the real enemy here. Once an employee fully understands what's at stake (i.e. the possibility of brain damage or even death), behavior changes almost instantly and complacency evaporates. (Note: The BasicSafe Training Tool can help you with that.)



Heat stress can be quite sneaky because it creeps up on ya slowly. You push a little more and a little more, and before you know it, you're getting dizzy and nauseous.

The good news? Heat is quite predictable and, therefore, preventable. However, when warning signs are not known or even ignored, things can get dangerous fast, especially when an employee is operating any type of machinery.

The most common symptoms of heat stress:

  • Excessive sweating
  • Dizziness
  • Excessive thirst
  • Dark-colored urine (from dehydration)
  • Weakness
  • Confusion
  • Fatigue
  • Muscle cramps
  • Headache
  • Pale skin
  • Rapid heartbeat
  • Nausea
  • Paleness
  • Diarrhea
  • Vomiting
  • Fainting / Loss of consciousness
Furthermore, individuals who...
  • have consumed alcohol within the last 24 hours
  • have been taking certain medications (colds, allergies, congestion, blood pressure, etc),
  • suffer from high blood pressure or other cardiac conditions
...are all at additional risk due to decreased heat tolerance. 
heat stress prevention

Occupational Heat Stress

Occupational heat exposure affects millions of workers in the U.S. Thousands get sick from extreme heat every year. Some of these cases result in death. 

Quick stat: According to the Bureau of Labor Statistics, 39 people died in 2016 from exposure to environmental heat.

From construction workers in Phoenix’ summer heat (we’re talking 114℉ on average) to metal smelters or folks who work in non-air-conditioned warehouses, heat not only jeopardizes workplace safety but also has massive, negative effects worker performance.

Quick Tip For Safety Managers: Keeping policies and procedures up-to-date and easily accessible for workers can go a long way. The BasicSafe Policy & Procedures Tool can help you with that.


Risk Factors:

  • Hot environmental conditions (high temperature & humidity, direct sun exposure, no breeze or wind, radiant heat sources)
  • Heavy physical labor (workload / amount of muscular exertion required)
  • Insufficient acclimatization
  • Contact with warm or hot objects
  • Type of PPE - Clothing that holds in body heat (i.e. waterproof clothing)
  • Low liquid intake
  • Lack of training

Lack of Acclimatization

According to OSHA, 50-70% of outdoor fatalities take place in the first few days of working in hot environments. Why? Because the body needs time to build up a tolerance to heat exposure. This happens gradually. This adaptation process of the body is called “heat acclimatization”. Insufficient acclimatization poses a significant risk that needs to be considered and addressed. Consider implementing an acclimatization schedule. The CDC recommends the following:

"For new workers, the schedule should be no more than a 20% exposure on day 1 and an increase of no more than 20% on each additional day. For workers who have had previous experience with the job, the acclimatization regimen should be no more than a 50% exposure on day 1, 60% on day 2, 80% on day 3, and 100% on day 4."

Not JUST outdoor workers are at risk

Hazardous heat exposure can occur indoors as well. Furthermore, it is important to note that heat exposure is not only limited to summer or during heat waves but can occur during any season, even winter, given the conditions are right. 

Workers in the following industries are particularly at risk of heat stress:

  • Agriculture
  • Construction
  • Landscaping
  • Mail & Package Delivery
  • Oil & Gas
  • Hazardous waste sites
  • Bakeries, Kitchens, Laundries
  • Boiler Rooms
  • Firefighters
  • Iron & Steel Mills
  • Manufacturing
  • Warehouse workers
  • Mining
  • Plants (i.e. chemical plants)


Heat stress is no fun for individuals but what about its effects on businesses? Particularly at scale, heat stress can cause a significant decline in worker productivity as well as an increased risk of accidents. 

When overheated, an employee's reaction time, attention, and multitasking capability becomes less reliable. In the early stages, heat stress often masquerades as inattention, distraction, or slight confusion.




Let's get practical. Here's what you can do to prevent heat stress in the workplace.


Knowledge is power. The first step to heat stress prevention is to know the signs & symptoms of heat stress. As a safety manager, it is absolutely imperative to educate employees on how to identify the early tell signs of heat stress so that appropriate measures can be taken immediately before things turn ugly. (Note: The BasicSafe Training Tool can help you with that.)


#2 Breaks & Fluids.

Taking breaks in the shade (if the work is performed outside) and proper fluid intake are the obvious choice. After all, most heat-related issues stem from dehydration. The average (healthy) person can tolerate up to 3-4% body water loss before experiencing significant symptoms (see list above). Already at only 2% body water loss (dehydration), a person’s cognitive abilities are massively compromised. When we sweat we not only lose water but also important electrolytes (often referred to as salts), i.e. sodium, potassium, and calcium. Popular electrolyte drinks include Gatorade (and similar sports drinks), Pedialyte, Coconut water, or Watermelon water. So, take a break, drink plenty of water, and, ideally, also have an electrolyte beverage at-hand if needed.

heat stress prevention#3 Cool Down with "Tech".

From air conditioning and cooling fans to cooling vests, there are many innovative options nowadays to decrease or virtually eliminate heat exposure. Cooling vests, for example, use cooling substances (freezer or gel packs) to help keep the body's temperature more stable. The downside is that they often only last 2-4 hours.

#4 Clothing.

Some clothing & PPE makes it easy for the body to overheat. A general rule of thumb: the heavier the clothing, the longer it takes for the body to cool down. But there is a lot that can be done just by wearing clothing that is appropriate for hot environments such as sun hats, breathable, light-colored, or even wetted clothing. Unfortunately, many of the really "hot jobs" also happen to be the ones that require heavy PPE. If wearing fewer layers is not an option, pay special attention to materials and breathability.

#5 Teamwork.

Every employee should have a designated "work buddy". Since workers don't always recognize the warning signs of heat stress themselves, co-worker can help spot issues before things escalate – provided they know what to look out for. One of the less-talked-about issues when it comes to heat stress is ego and complacency. Workers might not want to show 'weakness' and push through, particularly when they're newer. Encourage employees to look out for each other by partnering people up so they can periodically ask each other how they're feeling.


Risk assessment

To properly size up the risk at-hand, one may use technical methods such as calculating the “wet bulb globe temperature" of the worksite. Besides the temperature, important variables here are air movement, humidity, and radiant heat sources. There are so-called OELs (occupational exposure limits) that may be considered. 

Furthermore, certain states are more at risk than others such as Texas, California, and Kansas — these states have the highest rates of occupational heat stress.

OSHA & NIOSH (National Institute for Occupational Safety and Health) have collaborated and came up with the OSHA-NIOSH Heat Safety Tool App that can be useful in providing real-time information regarding weather conditions and heat index.


OSHA's Heat Stress Awareness Campaign

In 2011, OSHA launched its Heat Stress Prevention campaign under the catchphrase "Water. Rest. Shade. Keeping Workers Safe in the Heat" to raise awareness and educate employers as well as workers of the danger of heat stress. Millions have since gone through their heat stress prevention training. 



Heat stress is easy to underestimate. When early telltale signs are unknown or even ignored, it can not only cause accidents and physical harm but a significant decline in worker productivity which is obviously bad for business. The good news is that heat stress is rather predictable and easy to prepare for. Take advantage of these tips to protect your guys so that everybody can stay cool and return home safely.

We truly hope you got some value from this article. If you're interested in making your job as a safety manager a lot easier, feel free to reach out or get a quick, custom quote here. We can give you the tools to help you manage the safety and health of your business environment.

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