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Heat illness prevention

Business | August 1, 2021 | By:

Ways to keep workers safe during extreme temperatures.

High temperatures during the summer months can pose dangerous risks to outdoor workers. Each year, thousands of workers in the U.S. become sick from occupational heat exposure, and some cases are fatal. According to the Occupational Safety & Health Administration (OSHA), 50-to-70-percent of outdoor fatalities occur during the first few days of working in warm or hot environments due to a lack of heat acclimatization. Other factors that may lead to heat illness include high temperatures, high levels of humidity, direct exposure to sun and low fluid consumption.

Heat illness is preventable, and every employer should take special care to ensure their employees remain safe while on the job. The following content—gathered from OSHA and the National Institute for Occupational Safety & Health (NIOSH)—provides an overview of heat-related illnesses as well as tips for keeping outdoor workers cool and comfortable during the heat. 

Heat-related illnesses

Heat-related illnesses, such as heat exhaustion or heat stroke, occur when the human body is not able to properly cool itself. Normally, the body cools itself by sweating. However, during times of extreme heat, sweating may not be enough to regulate and maintain a healthy body temperature. The following are illnesses that may result from exposure to heat.

Heat stroke is the most serious heat-related health problem and occurs when the body is unable to control its temperature. When heat stroke occurs, the body’s temperature can rise to 106°F or higher within 10 to 15 minutes and may result in death.  

Symptoms to watch for: 

  • Confusion/slurred speech
  • Hot, dry skin or profuse sweating
  • Loss of consciousness
  • Seizures

How to help: Call 911 immediately. Move the worker to a shady area and remove outer clothing. Place cold wet towels or ice on head, neck, armpits and groin, and circulate the air around the worker to speed cooling.  

Heat exhaustion is the next most serious heat-related health problem and is the body’s response to a loss of water and salt through excessive sweating. 

Symptoms to watch for:

  • Headache
  • Nausea
  • Irritability
  • Dizziness
  • Weakness
  • Confusion
  • Heavy sweating

How to help: Remove the worker from the hot area and offer liquids to drink. Cool the worker with cold compresses to the head, neck and face, and encourage frequent sips of cool water. Workers with signs or symptoms of heat exhaustion should be taken to a clinic or emergency room for medical evaluation and treatment. If symptoms worsen, call 911. 

Heat cramps are muscle pains usually caused by a loss of body salts and fluids during sweating. Heat cramps may also be a symptom of heat exhaustion.

Symptoms to watch for: 

  • Muscle cramps
  • Pain 
  • Spasms in the abdomen, arms or legs

How to help: Encourage the worker to drink water and/or carbohydrate-electrolyte replacement liquids (such as a sports drink) every 15 to 20 minutes.  Seek medical help if the worker has heart problems, is on a low-sodium diet or if cramps do not subside within one hour. 

Heat rash is the most common problem in hot work environments and is a skin irritation caused by excessive sweating during hot, humid weather. 

Symptoms to watch for: 

  • A red cluster of pimples/small blisters that appear on the neck, upper chest, groin, under the breasts and in elbow creases. 

How to help: A cooler, less humid work environment is the best treatment. Keep the rash area dry and avoid ointments and creams. Powder may be
applied to increase comfort.  


Heat-related illness is preventable, especially when managers are diligent in providing effective controls. To ensure the safety of your workers, OSHA recommends that employers:

  • Ensure cool drinking water is available and easily accessible throughout the day.
  • Provide workers with fully shaded or air-conditioned areas for resting and cooling down.
  • Consider modifying/altering work schedules to reduce exposure to heat (rotate workers and split shifts, add additional workers, schedule more physically demanding work during the cooler times of the day, etc.).
  • Encourage the use of hats and light-colored, loose-fitting clothing.
  • Monitor weather reports daily.
  • Have an emergency plan in place and communicate it to supervisors and workers.

For more information on how to protect workers from the effects of heat, visit

SIDEBAR: High-risk factors

Factors that may lead to heat illness
in workers include:

  • High temperature and humidity.
  • Direct sun exposure (with no shade).
  • Limited or lack of air movement.
  • Low fluid consumption.
  • Physical exertion.
  • Lack of recent exposure to hot working conditions.
  • Heavy personal protective clothing and equipment.

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