Preventing Heat Stroke at Work

Summer’s here, and on some days it’s brutally hot out there. To beat the heat, people seek out shady spots, a cold beverage, or air conditioning whenever and wherever possible. But what about workers whose jobs require spending time in excessively hot and humid environments? For them, the heat—indoors or out—can be downright dangerous. Thousands of workers become sick from heat exposure at work every year, and some of those workers die from heat stress. These illnesses and deaths are preventable with workplace safeguards and training in place. Read on to learn how to keep your workers cool and healthy when temperatures rise.   

What is the Employer Responsibility?

Employers are required to maintain a workplace that “is free from recognizable hazards that are causing or likely to cause death or serious harm to employees,” under the Occupational Safety and Health (OSHA) Act of 1970. This includes protecting workers from heat exposure. Additionally, some states have OSHA-approved occupational safety and health programs that are required to meet OSHA standards but may include different or more rigorous workplace safety requirements.

Workplaces With High Risk of Heat Stress

Anyone on any job whether it’s indoors or outdoors can succumb to heat stress when temperatures rise. However, certain workplaces, workers, and work requirements elevate the risk of heat exposure incidents in employees.

Conditions that increase the risk of heat stress:

  • High air temperatures
  • Direct sun exposure
  • Lack of air circulation
  • Radiant heat sources, such as boilers and ovens
  • Direct contact with hot objects
  • Strenuous physical activity
  • Heavy equipment or gear

Examples of workplaces that present high risk of heat exposure:

  • Commercial Kitchens and Bakeries
  • Construction Sites
  • Factories
  • Manufacturing Operations
  • Restaurants and Catering Facilities
  • Laundries
  • Landscaping
  • Farming & Agriculture
  • Logistics Facilities

Workers who are most susceptible to heat stress:

  • Workers who are new or returning to work after a break.
  • Workers Age 65+
  • Workers with heart disease
  • Workers with high blood pressure
  • Workers who are obese

Other risks related to workplace heat exposure include burns from hot equipment and accidents due to sweaty palms, dizziness, and vision impaired by foggy protective eyewear.

What Causes Heat Stress?

In hot environments, your body maintains a stable and safe internal temperature through blood circulation and sweating. This process is less efficient when the ambient temperature is as hot or hotter than your body because blood circulating to your skin can’t cool down. When this condition occurs, your body will sweat to reduce internal temperatures. However, sweating becomes ineffective when humidity is high because the sweat doesn’t evaporate, which facilitates the cooling. Sweating is also only effective when lost fluids and salts are adequately replenished. When your body’s cooling mechanisms don’t work, your core temperature and heart rate rise. When this happens, you are at risk of heat stroke, heat exhaustion, heat cramps, and heat rash.

Heat-Related Illness Symptoms and First Aid

(This is intended as a guide for first-steps and is not a substitute for professional medical care.)

Heat Stroke Symptoms:

Heat stroke is a serious medical emergency that can cause death. Symptoms will not abate without medical intervention. Call 911 if any of the following symptoms are observed in your workers:

  • Confusion
  • Fainting
  • Seizures
  • Very high body temperature
  • Vomiting
  • Excessive sweating OR hot, dry skin
  • Rapid pulse
  • Rapid heart rate
  • Headache

While waiting for emergency help, administer the following First Aid:

  • Move the worker to a cool, air conditioned, or shady spot
  • Give them cool water
  • If available, give them sips of a sports beverage in addition to water
  • Avoid sugary or alcoholic beverages, which can inhibit body temperature regulation
  • Loosen clothing and remove outer layers
  • Place cold packs in armpits
  • Fan the worker, wet them with cool water, apply cool packs and compresses, or ice if available
  • Stay with the worker

Heat Exhaustion Symptoms:

Heat exhaustion is a serious medical condition that is the precursor to heat stroke. Call 911 if the following symptoms worsen or don’t improve within one hour:

  • Cool, moist skin, often with goosebumps
  • Heavy sweating
  • Fast heart rate
  • Headache
  • Nausea or vomiting
  • Dizziness or light-headedness
  • Fainting
  • Weakness
  • Thirst
  • Irritability

First Aid for Heat Exhaustion:

  • Move worker to cool, shady spot
  • Give worker plenty of cool water or other sport drinks
  • Cool them with ice packs or cold compresses
  • The worker should not return to work the same day
  • Take them to a clinic or the emergency room if symptoms worsen, or do not improve within one hour

Heat Cramp Symptoms:

  • Muscle spasms in abdomen, arms, or legs
  • Pain in abdomen, arms, or legs

First Aid for Heat Cramps:

  • Move worker to cool, shady spot
  • Have them drink cool water or other cool beverage
  • Worker should wait several hours before resuming strenuous work
  • Worker should see a doctor if cramps do not subside

Heat Rash Symptoms:

  • Clusters of red bumps on the skin, usually on the neck, upper chest, or folds of the skin

First Aid for Heat Rash:

  • Worker should be in a cooler, less humid environment if possible
  • Worker should keep the affected areas dry

Strategies to Prevent Heat Stress at Work

Workplace Best Practices

As an employer, it is critical to establish an emergency plan for heat related illnesses.  The plan should outline what should happen as soon as a worker shows signs of heat stress so that they receive immediate medical attention. Other important workplace precautions:

  • Establish a buddy system, where every worker has another employee assigned to observe them for signs of heat stress and take appropriate action when needed.
  • Give workers time to acclimate to working in a hot environment when they are new to the job or returning after a break or vacation.
  • Offer plenty of potable water near the worksite and encourage your workers to drink small amounts frequently.
  • Periods of work in high heat should be short. Schedule frequent periods of rest in shady spots, or in cool break rooms.
  • Rotate work assignments for employees between strenuous and lighter labor to prevent overexertion.
  • If possible, schedule the most strenuous outdoor work for cooler times of day.
  • For certain extreme work environments, physical monitoring of employees may be necessary.


All supervisors and workers should know:

  • How to prevent heat related illnesses
  • How to spot the signs of heat related illnesses in themselves and others
  • The importance of immediately reporting these symptoms to a supervisor or someone who will take action
  • First aid and emergency protocols for heat related illnesses

Environmental and Protective Equipment:

Whenever possible, provide environments where your workers can cool down, such as air conditioned break rooms. Place cooling fans in the work area to increase air circulation. Provide adequate ventilation, as well as exhaust ventilation above high heat equipment, such as ovens and laundry machines. Hot equipment should be insulated. Extremely hot conditions may require specialty cooling gear, such as insulated or reflective clothing, jackets that contain ice packs, or technical garments with built-in cooling systems.

Fortunately, heat-related illnesses are preventable. Establishing heat stress prevention and awareness programs, along with clear action plans to care for workers exhibiting heat stress symptoms, will make your workplace safe when conditions are hot. Most importantly, these measures will save lives.

For more information about OSHA standards, workplace recommendations, and industry-specific resources, visit the Occupational Heat Exposure page of the Occupational Safety and Health Administration or the Occupational Heat Stress page of the Centers for Disease Control and Prevention.