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First Aid: Recognizing and Responding to Heat Stress

With rising August temperatures in and around the plant, safety managers must be aware of signs and symptoms of worker heat stress.

Recognizing and responding to the warning signs of heat stress can mean the difference between life and death. And preventing heat stress and heat-related illness means never having to face the frightening prospect of serious heat-related illnesses in the first place.

Ramon Ryan, MD suggests these following for identifying and responding to such illnesses before they become life-threatening, and secondly offers tips to prevent them from occurring at all.

Recognize the Illnesses Heat Edema
Leading to swelling of extremities, heat edema usually occurs during the first several days of exposure to exposure to extreme heat. Afterwards, the body usually self-acclimates, and no treatment is necessary.

Heat Cramps
Exertion in hot environments leads to excessive sweating, causing heat cramps, which should be treated by discontinuing physical activity and replenishing fluids and electrolytes orally or, in more extreme cases, intravenously.

Heat Syncope
A combination of environmental heat and quickly standing from a sitting or squatting position causes heat syncope. The condition, most common among persons who have recently consumed alcoholic beverages, should be treated by elevating the legs and replenishing fluids. The sufferer should be monitored closely to guard against airway obstruction by the tongue or vomitus.

Heat Exhaustion
When the body loses excessive water and/or salt, heat exhaustion occurs. This condition may be accompanied by increased core body temperatures (less than 105º). Fatigue, dizziness, impaired judgment, headache, cramps, weakness, nausea, vomiting, and diarrhea may occur, along with increased heart rate with either normal or low blood pressure. The sufferer's body must be cooled immediately and fluids and electrolytes replaced either orally or intravenously. Heat exhaustion is a dangerous condition quickly escalating to heat stroke if not treated immediately.

Heat Stroke
Heat Stroke is a life-threatening condition progressing from heat exhaustion. Core body temperature rises to 105º or greater, accompanied by increased heart rate and decreased blood pressure. Skin becomes warm, dry and flushed, but may grow pale if the person goes into shock. Delirium, convulsions and coma may occur. Death may result with untreated persons. Heat stroke is a life-threatening medical emergency requiring immediate hospital treatment.

An Ounce of Prevention
Workers in hot environments should take frequent breaks from heat and prolonged exertion, and maintain healthy fluid levels by drinking at least 8 ounces of water every half-hour. Also, employers must train workers to recognize warning signs of oncoming heat stress, in themselves and in co-workers, because many heat-related illnesses are accompanied by lack of judgment by the sufferer. At the first sign or symptom of heat stress, the sufferer should remove himself from heat and cease physical exertion.

Allow 10 to 14 days for new workers to acclimate to hot temperatures. Gradual exposure increased over time is the best approach to working in hot conditions. And remember that high humidity decreases the body's ability to cool itself, and that the body can only acclimate so fast and so far.

Ryan adds that the old habit of taking salt tablets is an unhealthy one; instead, electrolyte replacement combined with fluid intake is recommended for prevention.

Increased Risk Factors Age
People 65 and older are at increased risk for heat illnesses.

Medications such as antihistamine, tricyclic antidepressants and alcohol increase the risk of dehydration.

High temperatures and humidity put everyone at greater risk of suffering from heat illnesses.

Prolonged exposure to heat, especially when combined with exertion, or exposure to heat prior to proper acclimatization increases risk of heat stress.

Taken from Plant Safety and Maintenence Premier Edition, August 2007