Working in High Heat Conditions

Many people are exposed to heat on the job, in both indoor and outdoor heat environments. Operations involving high air temperatures, radiant heat sources (e.g., sunlight, hot exhaust), high humidity, direct physical contact with hot objects, or strenuous physical activities have a high potential for causing heat-related illness. Every year, workers die and thousands more become ill while working in extreme heat or humid conditions. More than 40 percent of heat-related worker deaths occur in the construction industry, but workers in every field are susceptible.

Workers who are suddenly exposed to working in a hot environment face additional, but generally avoidable hazards to their safety and health. New workers and those returning from time away are especially vulnerable. That's why it is important to prepare for the heat: educate workers about the dangers of heat, and acclimatize workers by gradually increasing the workload or providing more frequent breaks to help new workers and those returning to a job after time away build up a tolerance for hot conditions.

Environmental heat exposure alone is directly associated with an average of more than 600 fatalities each year in the U.S making heat the leading cause of weather-related deaths, above lightening, tornadoes, hurricanes, and floods combined. Despite the potential of heat stress as an occupational hazard, there are no federal government standards to protect workers. OSHA enforces the protection of workers from heat stress under the General Duty Clause which states that employers are required to provide their employees with a place of employment that "is free from recognizable hazards that are causing or likely to cause death or serious harm to employees."

OSHA has launched a Heat Illness Prevention campaign which educates employers and workers on the dangers of working in the heat. Visit the site to learn more about heat related illness symptoms, to obtain educational and training materials, videos, and to download the OSHA-NIOSH Heat Safety Tool (HST) Smartphone App. The HST app provides weather information, heat index, risk factors, heat illness symptoms and first aid measures.

Any employer with workers exposed to high temperatures, at any time of year, should establish a complete heat illness prevention program. Three things to keep in mind to prevent heat related illnesses are Water - Rest - Shade. OSHA has built a campaign around these three words.

Heat Related Illnesses are Preventable

Provide any workers exposed to heat with sufficient amounts of water, rest and shade.
Allow new or returning workers to gradually increase workloads and take more frequent breaks as they acclimatize, or build a tolerance for working in the heat.
Plan for emergencies and train workers on prevention.
Monitor workers for signs of illness.

Types of Heat-related Illnesses

There are a range of heat illnesses and they can affect anyone, regardless of age or physical condition. Know the symptoms of each which are clearly described on the OSHA-NIOSH Heat Safety Tool smartphone app.

Heat stroke, the most serious form of heat-related illness, happens when the body becomes unable to regulate its core temperature. Sweating stops and the body can no longer rid itself of excess heat. Signs include a very high body temperature, red, hot and dry skin, confusion, loss of consciousness, and seizures. Heat stroke is a medical emergency that may result in death! Call 911 immediately.

Heat exhaustion is the body's response to loss of water and salt from heavy sweating. Signs include headache, nausea, dizziness, weakness, irritability, thirst, and heavy sweating.

Heat cramps are caused by the loss of body salts and fluid during sweating. Low salt levels in muscles cause painful cramps. Tired muscles—those used for performing the work—are usually the ones most affected by cramps. Cramps may occur during or after working hours.

Heat rash, also known as prickly heat, is skin irritation caused by sweat that does not evaporate from the skin. Heat rash is the most common problem in hot work environments.

First Aid

Below are basic first aid measures. Refer to OSHA’s Heat-related Illness and First Aid page and/or the OSHA-NIOSH Heat Safety Tool Smartphone App for additional information.

First aid for heat stroke, heat exhaustion, and heat cramps are similar. For all heat related illness except for heat rash, move the victim to a cool, shaded area, loosen and/or remove outer clothing, cool the victim with cool water, cool compresses, and/or ice packs, and provide fluids (preferably water).

If heat stroke is even remotely suspected, immediately call 911 and stay with the worker until help arrives.

For heat exhaustion, the affected worker should be taken to a clinic or emergency room for medical evaluation if signs or symptoms worsen or do not improve within 60 minutes. Even if the worker does feel better, he/she should not return to work that day.

For heat cramps, affected workers should wait several hours before returning to work and should seek medical attention if the cramps don’t go away.

Heat Rash is best treated by moving the affected worker to a cooler and less humid environment, if possible, and by keeping the affected body areas dry.