Employees’ exposure to high air temperature and relative humidity, radiant heat from the sun and other heat sources cause medical conditions that lead to the stages of heat illness. Working conditions, including workload, protective clothing and PPE, and limited movement of air also lead to stages of heat illness.

Prevention is key. Employees who wait to take such steps as drinking water and accessing shade, until symptoms appear are at greater risk. Progression to serious illness can be rapid.

The following people bear a greater risk of heat illness than others:

Adults over the age of 65;
People who are physically ill, particularly if they have heart disease and high blood pressure;
People who are overweight; and
People who take certain medications, including common medications as antihistamines, blood pressure medications and diuretics. These medications affect the body’s ability to retain water and respond to heat. Tell physicians who provide industrial medical examinations for companies that employ outdoor workers if an employee is likely to be exposed to extreme heat. The physician can then provide proper counseling.

Recognizing Conditions That Create Heat Illness

Avoiding Heat Illness