19 Jun Preventing Heat Stress

Preventing Heat Stress

Preventing heat stress requires recognizing heat-related hazards early, staying hydrated, allowing workers to acclimatize, and responding immediately when symptoms develop.

Heat stress can occur when the body cannot adequately cool itself during work in hot or humid conditions. Physical exertion, direct sunlight, protective clothing, limited air movement, and inadequate hydration can increase the risk. Heat-related illnesses can progress quickly and may become life-threatening if warning signs are ignored.

Heat-Related Illnesses

Heat Cramps

Heat cramps are painful muscle spasms that can occur during or after strenuous work in the heat. Heavy sweating and the loss of fluids and electrolytes can contribute to cramping.

If heat cramps occur:

• Stop strenuous activity and rest in a cool or shaded location.
• Drink water or an appropriate electrolyte-containing beverage.
• Do not resume strenuous work for several hours after the cramps subside.
• Seek medical attention if cramps do not improve or other symptoms develop.

Heat Exhaustion

Heat exhaustion occurs when the body loses excessive amounts of water and salt through sweating. Symptoms may include:

• Heavy sweating.
• Cool, pale, or clammy skin.
• Headache or dizziness.
• Weakness or fatigue.
• Irritability or confusion.
• Nausea or vomiting.
• Thirst.
• Rapid heartbeat.
• Muscle cramps.

Move the worker to a cooler location, remove unnecessary clothing, cool the worker with cold compresses or water, and provide frequent sips of cool water if the worker is alert and able to drink. Obtain medical evaluation when symptoms are severe, worsen, or do not improve.

Heat Stroke

Heat stroke is a life-threatening medical emergency that occurs when the body’s temperature-control system fails.

Warning signs can include:

• Confusion, altered behavior, or slurred speech.
• Loss of consciousness or seizures.
• Very high body temperature.
• Hot skin that may be either dry or sweaty.
• Rapid pulse and breathing.

Do not rely on the absence of sweating to identify heat stroke. A person experiencing heat stroke may still be sweating.

Call 911 or emergency medical services immediately and begin rapidly cooling the worker while waiting for help. Move the person to a cool or shaded area, remove unnecessary outer clothing, and cool with cold water, wet towels, ice, or other available methods. Never leave the worker alone.

Preventing Heat Stress

Acclimatization

Workers need time to gradually adjust to working in the heat. New workers and employees returning after an extended absence should have their heat exposure increased gradually.

Full acclimatization generally develops over approximately 7 to 14 days, depending on the worker and conditions. Supervisors should closely monitor employees during this adjustment period.

Hydration

Do not wait until you are thirsty to drink water.

• Drink cool water frequently throughout the work period.
• For moderate work lasting less than two hours, OSHA and NIOSH generally recommend about one cup of water every 15–20 minutes.
• During prolonged sweating lasting several hours, electrolyte-containing beverages may help replace electrolytes lost through sweat.
• Avoid alcohol before and during heat exposure.
• Do not rely on highly caffeinated or sugary beverages for hydration.

Workers generally should obtain needed salt through normal meals rather than taking salt tablets unless specifically directed by a healthcare professional.

Work Practices

When working in hot conditions:

• Schedule strenuous tasks during cooler portions of the day when practical.
• Take appropriate rest breaks in shaded, air-conditioned, or otherwise cool areas.
• Use ventilation, fans, shade, or other engineering controls where appropriate.
• Wear lightweight, loose-fitting, breathable clothing when work conditions permit.
• Consider the additional heat burden created by protective clothing and PPE.
• Use a buddy system so workers can watch one another for symptoms.
• Increase monitoring when temperatures, humidity, workload, or protective clothing increase heat exposure.
• Report symptoms immediately rather than trying to “work through” them.

Remember

Preventing heat stress depends on recognizing symptoms before they become an emergency. Drink water frequently, take appropriate rest breaks, acclimatize gradually, and immediately report signs of heat-related illness.