Managing Heat Stress and Working In Hot Environments

Information provided by ACPA and Travelers Insurance

When working in hot environments body temperature may rise, and the body responds by sweating. As the sweat evaporates it cools the body. If the process does not work several heat related illnesses may occur. Water is key to this process by providing adequate blood volume to transfer heat outward and perspiration to cool the body.

Other factors:

• Humidity which may inhibit evaporation of sweat.
• Inadequate water intake.
• High ambient air temperature or radiant heat from blast furnaces or sunshine.
• Various protective clothing that may add to the heat load of the employee.

Heat Related Illnesses

Heat Rash
Symptoms
Sweat duct becomes blocked and sweat accumulates in the gland. Heat rash is uncomfortable and can lead to more serious disorders due to lack of sweating.

First aid
Apply drying lotion and powder.

Prevention
Regular bathing keeps skin dry and clean.

Fainting
Symptoms
Common among workers not acclimated to working in hot environments. Caused by blood pooling in lower extremities.

First aid
Remove employee to cooler area and lay down briefly, recovery is prompt and complete.

Prevention
Proper acclimatization and avoid standing erect for extended periods of time; move around.

Heat Cramps
Symptoms
Painful spasms of the muscles used during or after work; caused by excessive loss of salt from sweating.

First aid
Consumption of electrolyte replacement beverage.

Prevention
Adequate salt intake during meals. No need for salt tablets, normal diet has ample salt. Begin drinking replenishing fluids one to two hours before beginning work in hot environment.

Heat Exhaustion
Symptoms
Fatigue, nausea, headache, rapid heart rate and moist clammy skin. Can progress to heat stroke.

First aid
Rest in cool area and drink fluids. Severe cases may require intravenous fluids.

Prevention
Acclimatization of worker and drinking ample water during work.

Heat Stroke
Symptoms
Elevated body temperature, unconsciousness or convulsions, lack of sweating and possible vomiting and diarrhea.

First aid
A medical emergency that requires professional medical treatment. Move patient to cool area, bath in cool water or cover in cool water soaked towels. Remove outer clothing and treat for shock. Give no oral liquid if convulsing or unconscious.

Warning: Pregnant women, especially in the first trimester, are at increased risk for birth defects if body temperature is evaluated for extended periods of time. Consult a physician.

Administrative Controls

Adequate fluid intake
Drink ample fluids throughout the day.

• BEST: plain cool (50-60 degrees F) water.
• AVOID: alcohol, caffeinated beverages such as tea and coffee which are diuretics, and excessive carbohydrates such as soda and fruit juice which can inhibit water uptake.
• Increase rest periods throughout the day.
• Job rotation for high exposure jobs.
• Schedule hot work for cooler periods in the day.
• Employee and supervisor training on heat related issues.

To encourage workers to drink water is should be readily accessible and kept clean and cool.

Acclimatize workers
Acclimatized worker will have increased ability to work in heat and be more resilient to the stress. The process takes 4 to 7 days and there is a substantial loss when workers leave the work routine for one week or more and must be reacclimatized.

Medical evaluation
A physician can help identify high risk groups that are more susceptible to heat stress. Screen for the following: