Heat Stress Prevention

In this video, we’re going to learn about how heat stress can affect our body and how to remain safe when it arises.

HubSpot Video

What is Heat Stress?

So, what is heat stress?  Heat stress can be a variety of illnesses is caused by exposure to higher than normal temperatures.  It often occurs when the body is unable to maintain a healthy temperature when exposed to extreme conditions. 

You may know this can happen when working under the hot summer sun, but did you know it can also occur during the wintertime when you’re bundled up in a heated building or garage? Regardless of the temperature outside, our bodies are mostly concerned with what’s happening on the inside.

The human body is an extraordinary system and it’s capable of performing a variety of demanding tasks, but heat stress can often interfere with the natural processes required to keep us alive.  Things such as breathing, digesting, and even our heart beating. As you can imagine, when these processes stop functioning, the results can be serious or even fatal.     

The Good News

The good news is that our bodies have an automatic cooling system built in. With proper training, most of these heat-related illnesses are entirely preventable.

One of these built-in defenses is our blood.  Did you know that the circulation of blood flow can help lower our body temperatures? For most, the ideal body temperature is 98.6 degrees. As our body temperature rises, the circulatory system directs more blood flow to the surface of our skin and carries the internal heat of our bodies up to the skin where it can be released into the air.

When more cooling power is needed, our sweat glands will also go to work by moving heat out of the body in the form of warm water. Once this water reaches our skin, it is then wiped away or evaporated into vapor form.

Both of these systems are effective, but they do r take their toll on the body and require excessive amounts of water to stay fully operational. When the body cannot dispose of excess heat fast enough, these natural cooling defenses begin to break down and put us in danger of developing heat-related illnesses.

Drink Water Regularly

Did you know we can sweat out up to one quart of water and electrolytes an hour?  This depletion of water and electrolytes often causes heat-related illnesses. One way to know if you’re running low on water is an extreme thirst that can develop throughout the day. However, we can't rely on thirst alone.  Many times, feeling thirst may be a sign that heat illness symptoms have already begun. 

To prevent this threat from happening, we need to make a conscious effort to take in even more liquids throughout the day. When sweating, aim to drink 5 to 7 ounces of water every 15 or 20 minutes.   It’s important to note that not all liquids are created equally. Gatorade or other electrolyte drinks can be a great alternative to water because they're formulated to replace the minerals that often get depleted through sweat, but sugar-infused energy drinks, soft drinks, or alcohol will accelerate dehydration. 

Different Types of Heat-Related Illnesses

When it comes to heat-related illnesses, there are 5 different types every employee should be aware of when working in the field.   These types include rashes, cramps, fainting, exhaustion, and stroke.

Heat Rash: Heat rash occurs when the skin's sweat glands are blocked and sweat cannot get to the surface of the skin to evaporate. This causes inflammation and results in a rash. Common symptoms of heat rash include red bumps on the skin and a prickly or itchy feeling to the skin (also known as prickly heat).  Treatment for a heat rash includes moving to a cool environment, a cold shower, and thoroughly drying the area.  Infection can occur if the rash is not cleaned quickly enough.

Fainting: Fainting can occur when our body tries to cool down by directing blood to the skin instead of to other more critical parts of the body.  Warning signs that a loss of consciousness from heat illness is imminent include a rapid heartbeat and dizziness.  Fainting often occurs in people who are new to working in high heat conditions or are less mobile while working in the heat. Moving around, rather than standing still can actually prevent fainting; however, most people will recover from fainting by lying down in a cool area.

Heat Cramps:  Heat cramps occur when we begin to sweat excessively and fail to replace the vital minerals and electrolytes that we're losing.  Symptoms for heat cramps include painful cramping as well as involuntary jerking or muscle spasms, mainly located in the large muscles.  Treatment for heat cramps are stretching, massaging the muscles, and rehydrating with an electrolyte beverage such as a low-sugar Gatorade drink.

Heat Exhaustion: Heat exhaustion occurs when our body is running low on both electrolytes and water. Heat exhaustion can often cause the individual to feel confused, dizzy, weak, or uncoordinated.  Individuals will often begin to sweat profusely and experience extreme thirst.  When exhaustion occurs, it often takes the body well over 30 minutes to cool down. Reverting to an air-conditioned building or truck is often the best treatment for heat exhaustion.

Heat Stroke:  Heat stroke is a more serious form of heat exhaustion and occurs when the body's natural cooling mechanisms completely break down. In circumstances when a heat stroke occurs, the victim is no longer able to sweat and their skin becomes to be very hot, dry, and flushed in color. Other symptoms include a throbbing headache, rapid heartbeat, nausea, or even vomiting.  Heatstroke causes a person's body temperature to rise to critical levels, which can cause internal damage to organs such as the brain or heart and can even be fatal.  In circumstances when you feel heat stroke is imminent, quickly contact 911 for medical assistance. While waiting for their arrival, do your best to get into an air-conditioned facility as quickly as possible. Do not supply anything by mouth until they arrive.

Responding to Heat-Illness

When you're experiencing any of the five types of heat stress, it's important to pay attention to what your body is telling you.  If you ignore the symptoms of heat rash, cramping, thirst, or even lightheadedness,  they can turn into a more serious form of heat exhaustion or heat stroke. Even when we do our best to protect ourselves from the heat, it can still end up affecting us or those around us. 

If you witness a co-worker develop a heat-related illness while on the job, please do your best to address the issue and encourage them to get out of the heat and into a cool environment. If they’re having mobility problems, help them sit or lie down to rest and cool. If you’re able, try to cool them off by pouring cold water over their head, face, and neck. You can also apply cold water with a wet towel. To speed up the cooling process, apply cold compresses to your armpits. You can also wet down their clothing and direct a fan on them.  Ice or cold packs also work great. 

Encourage them to drink water and an electrolyte drink if available. Encourage the victim to remove excessive outerwear and loosen any tight garments. If you think they may be experiencing heatstroke, call 911 for medical assistance immediately.  Stay with the victim and continue to cool them down until the EMTs arrive.

Risk Factors

Environmental factors and personal risk factors are often major contributors to heat-related illnesses.

Environmental factors are weather-related conditions such as high temperatures, high humidity, and limited air movement.  For example, if the temperature is 95⁰ outside and there is 50% relative humidity with little air movement, the real feel temperature could be well over 107⁰ Fahrenheit.  Add in direct sunlight and the real feel temperature could increase by 15 degrees. Other environmental factors include radiant heat, which is the direct sun shining down on you and conductive heat, which is the ground reflecting heat back up from the sun.

Personal Risk Factors are a major contributing factor in heat illnesses for a variety of reasons.  Those who are prone to have a higher risk of heat-related illness are those who are older in age, overweight, diagnosed with high blood pressure, smokers, have respiratory issues, drink excessive sugary drinks, or those who have previously suffered from heat illness. Those who are not acclimated with working in the heat are also at risk.  On average, it takes about 6-7 days for someone to properly adjust to outdoor heat and humidity.

Several prescriptions and over the counter medications can also greatly reduce sweating and increase urination, resulting in dehydration. Individuals working in the heat who are taking medications should always consult their doctors if symptoms develop.

Heat-Illness Prevention

Food Intake: At this point, we’ve learned that it’s important to drink 5 to 7 ounces of liquid every 15 or 20 minutes, but it’s also important to be conscious of what you eat throughout the day as well.  For example, hot or high-calorie meals will often raise your body’s internal temperature right after digesting. Your body can then mistakenly try to pump more blood to your stomach to help digest instead of helping you cool off.

Monitor Urine: An additional way to monitor your body for heat-related illnesses is to monitor your urine output to see if you need to be drinking more water and/or electrolyte beverages. Clearer urine is often a sign of hydration while dark yellow urine can often be a sign of dehydration.

Heat Prevention Accessories: Although we can’t always control the environments we work in, we can utilize a few additional accessories to help fight the heat. Some of these accessories could be wearing a light-colored hat and sunglasses to keep the hot sun off your face and head. Sunscreen also works great at preventing the sun from heating up your skin and protects you from dangerous UV rays.

Climate Controls If working indoors or in a vehicle, temperatures can also be controlled to allow for safe working conditions. Some of these climate controls include opening a window, air conditioning, circulating fans, and ventilation systems.


In conclusion, it’s important to remember that excessive heat can create real hazards in the workplace.  Understanding the problems and how to avoid them is the key to safe working conditions.

When working in the field, always take the time to get acclimated to the warmer temperatures. Drink water and electrolyte-based drinks regularly and try to eat low-calorie, cool meals throughout the workday.  Use climate controls whenever possible. Know what to look for if you or a co-worker develops heat-related symptoms and remember to always play it safe.