Heat Stress

Elevated heat and humidity, in addition to strenuous work, can place an abnormal stress on the body. When the body temperature rises even a few degrees above normal (which is about 98.6°F), it will experience muscle cramps, become weak, disoriented, and dangerously ill unless the body cools down. Body core temperature should not exceed 100.4°F and the average heart rate over a day should not exceed 110 beats per minute. If the body temperature rises above 105°F, the heat stress condition can be fatal. There is also a higher frequency of accidents in hot environments.

Persons working in hot environments - steam tunnels, mechanical rooms, power plants, outside during the summer, kitchens, laundries, and the like - must take special precautions against heat stress. The following guidelines can help you keep cool in the heat and avoid the dangerous consequences:

  1. Adapt To The Heat by gradually getting used to the hot environment over a one-week period of time. Each day, the workload can be increased slightly until you are able to operate at "full steam".
  2. Drink Water Frequently to replace the loss of body water during the sweating process. Ideally, you should drink at least 8 ounces of water every 20-30 minutes while working in the hot environment. Sweating is one of the ways your body cools itself down.
  3. Wear Personal Protective Equipment for hot environments which ranges from ordinary work clothes made from "breathable" fabrics to specially designed suits cooled by air, ice or portable air conditioners. "Non-breathable" fabrics may add to the heat stress factors.
  4. Use Engineering Controls such as fans, ventilators, exhaust systems, and air-coolant or conditioning systems to help reduce work site temperatures to more adaptable levels. Other controls such as heat shields and insulating heat-producing equipment (thermal system insulation) will also help lower the environmental temperature.
  5. Know The Signs, Symptoms and Treatment of heat stress (heat cramps, heat exhaustion & heat stroke) that affects a person's physiological and behavioral condition. After heat stress is identified, use of proper first-aid techniques and seeking medical attention will minimize the dangerous effects.

Please keep your cool, heat stress is dangerous but very preventable. EHS can review the workplace risk factors - such as a hot environment, high work demands, and protective clothing requirements - to make recommendations that minimize risk. Contact the EHS Industrial Hygienist at (573) 882-7018 for additional information or workplace risk factor review.