Heat stress is an illness that can be caused by exposure to extreme heat or work in hot environments. Exposure to heat can cause illness, injuries, or death. Heat stress occurs when the body cannot get rid of excess heat. When heat stress happens, the body’s core temperature rises and the heart rate increases. As the body continues to store heat, the person begins to lose concentration and has difficulty focusing on a task, which may become irritable or sick.
An increase in body temperature of two degrees Fahrenheit can affect mental functioning. A five-degree Fahrenheit increase can result in serious illness or death. The most serious heat illness is heatstroke. Other heat illnesses, such as heat exhaustion, heat cramps, and heat rash, should also be avoided. Factors that contribute to heat stress are high air temperatures, radiant heat sources, high humidity, direct physical contact with hot objects, and strenuous physical activities.
Workers at risk of heat stress include outdoor workers and workers in hot environments such as firefighters, bakery workers, farmers, construction workers, miners, boiler room workers, factory workers, and others. Workers at greater risk of heat stress include those who are 65 years of age or older, are overweight, have heart disease or high blood pressure, have drug use, have a low intake of liquids, or take medications that may be affected by extreme heat.
Table of Contents
Types of Heat-related Illnesses
Heat Stroke
Heatstroke is the most serious heat-related illness. It occurs when the body becomes unable to control its temperature: the body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. When heat stroke occurs, the body temperature can rise to 106°F or higher within 10 to 15 minutes. Heatstroke can cause death or permanent disability if emergency treatment is not given.
Symptoms of heat stroke
- Confusion, unable to think clearly, slurred speech
- Loss of consciousness (coma)
- Hot, dry skin or may stop sweating
- Seizures (fits)
- Very high body temperature
- Fatal if treatment delayed
Heat stroke first aid:
- Seek medical attention immediately. All heat stroke victims need hospitalization.
- Move the victim to a cool place. Remove heavy clothing; light clothing can be left in place.
- Cool the worker quickly with cold water or ice bath if possible; wet the skin, place cold wet clothes on the skin, or soak clothing with cool water.
- Circulate the air around the worker to speed cooling.
- To prevent hypothermia continue cooling the victim until their temperature drops to 102 degrees Fahrenheit.
- Care for seizures if they occur.
- Do not use aspirin or acetaminophen.
Heat Exhaustion
Heat exhaustion is the body’s response to an excessive loss of water and salt, usually through excessive sweating. Workers most prone to heat exhaustion are those that are elderly, have high blood pressure, and those working in a hot environment.
Symptoms of Heat Exhaustion-
- Headache
- Nausea or vomiting
- Dizziness
- Weakness
- Irritability
- Thirst
- Heavy sweating
- Elevated body temperature
- Decreased urine output
- Fast heartbeat
Heat exhaustion first aid:
- If medical care is unavailable, call the ambulance.
- Move the victim to a cool place.
- Keep the victim lying down with legs straight.
- Remove unnecessary clothing, including shoes and socks.
- Cool the victim by applying cold packs or wet towels or cloths. Fan the victim.
- Give the victim cold water if he or she is fully conscious.
- If no improvement is noted within 30 minutes, seek medical attention.
- If medical care is unavailable, call the ambulance.
Heat Rash
Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. Heat rash is the most common problem in hot work environments.
Symptoms of heat rash –
- Looks like a red cluster of pimples or small blisters.
- Usually appears on the neck, upper chest, groin, under the breasts, and in elbow creases.
Heat Rash First Aid –
- Try to work in a cooler, less humid environment when possible
- Keep the affected area dry.
- The powder may be applied to increase comfort.
- Ointments and creams should not be used.
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 cramps may also be a symptom of heat exhaustion.
Symptoms of heat cramps –
- Muscle cramps, pain, or spasms in the abdomen, arms, or legs.
First Aids of heat cramps –
- Have workers rest in a shady, cool area.
- Workers should drink water or other cool beverages.
- Wait a few hours before allowing workers to return to strenuous work.
- Have workers seek medical attention if cramps don’t go away.
Heat Syncope
Heat syncope is a fainting (syncope) episode or dizziness that usually occurs with prolonged standing or sudden rising from a sitting or lying position. Factors that may contribute to heat syncope include dehydration and lack of acclimatization.
Symptoms of heat syncope –
- Fainting (short duration)
- Dizziness
- Light-headedness during prolonged standing or suddenly rising from a sitting or lying position
First Aid of heat syncope
- Sit or lie down in a cool place.
- Slowly drink water, clear juice, or a sports drink.
How To Prevent Heat Illness:
Prevention of heat stress in workers is important and the precautions that can be taken any time temperatures are high and the job involves physical work. Employers should provide training to workers so they understand what is heat stress, how it affects their health and safety, and how it can be prevented.
- Establish a complete heat illness prevention program.
- Provide training about the hazards leading to heat stress and how to prevent them.
- Provide a lot of cool water to workers close to the work area. At least one pint of water per hour is needed.
- Modify work schedules and arrange frequent rest periods with water breaks in shaded or air-conditioned areas.
- Gradually increase workloads and allow more frequent breaks for workers new to the heat or those that have been away from work to adapt to working in the heat (acclimatization).
- Designate a responsible person to monitor conditions and protect workers who are at risk of heat stress.
- Consider protective clothing that provides cooling.
How employers can protect workers against heat stress
- Train workers in heat stress awareness and first-aid.
- Avoid beverages containing alcohol or caffeine.
- Provide drinking water.
- Wear lightweight, light-colored, loose-fitting clothes.
- Block out direct sun and other heat sources.
- Provide rest breaks and air-conditioned rest areas.
- Encourage workers to stay fit; to drink water.
- Indoors, provide fans for air movement.
- Use machines to reduce the physical demands of work.
- Schedule most strenuous work to cooler times of the day.