Working Safely in the Heat

Certain safety problems are common to hot environments. Heat tends to promote accidents due to the slipperiness of sweaty palms, dizziness, or the fogging of safety glasses. Wherever there exists molten metal hot surfaces, steam, etc., the possibility of burns from accidental contact also exists.

The frequency of accidents, in general appears to be higher in hot environments than in more moderate environmental conditions. One reason is that working in a hot environment lowers the mental alertness and physical performance of an individual. Increased body temperature and physical discomfort promote irritability, anger, and other emotional states, which sometimes cause workers to overlook safety procedures or to divert attention from hazardous tasks.

When the body is unable to cool itself through perspiration, serious heat illnesses can occur. The most extreme heat-induced illnesses are heat exhaustion and heat stroke. If not treated, heat related illnesses could lead to mental confusion, seizures or even death.

Heat Exhaustion
Heat exhaustion includes several clinical disorders having symptoms, which may resemble the early symptoms of heat stroke. Heat exhaustion is caused by the loss of large amounts of fluid by sweating, sometimes with excessive loss of salt.

Symptoms of heat exhaustion include:
    • Headaches, dizziness, and/or lightheadedness
    • Physical weakness, fainting, or passing out
    • Skin is clammy and moist, the complexion is pale or flushed
    • Body temperature is normal or only slightly elevated.

In most cases, treatment involves having the victim rest in a cool place and drink plenty of liquids. Victims with mild cases of heat exhaustion usually recover spontaneously with this treatment. Those with severe cases may require extended care for several days. There are no known permanent effects.

Heat Stroke
Heat stroke is the most serious of health problems associated with working in hot environments. It occurs when the body's temperature regulatory system fails and sweating becomes inadequate. The body's only effective means of removing excess heat is compromised with little warning to the victim that a crisis stage has been reached.

Symptoms of heat stroke include:
    • Dry, pale skin, with no perspiration
    • Hot red skin, resembling sunburn
    • Mentally confused, delirious
    • Convulsions, seizures.

Unless the victim receives quick and appropriate treatment, death can occur. Any person with signs or symptoms of heat stroke requires immediate hospitalization. However, first aid should be immediately administered. This includes:
    • Removing the victim to a cool area
    • Thoroughly soaking the clothing with water
    • Vigorously fanning the body to increase cooling.

Heat Cramps
Heat cramps are painful spasms of the muscles that occur among those who sweat profusely in heat, drink large quantities of water, but do not adequately replace the body's salt loss. The drinking of large quantities of water tends to dilute the body's fluids, while the body continues to lose salt. Shortly thereafter, the low salt level in the muscles causes painful cramps. The affected muscles may be part of the arms, legs, or abdomen, but tired muscles (those used in performing the work) are usually the ones most susceptible to cramps. Cramps may occur during or after work hours and may be relieved by taking salted liquids by mouth.

What Can Be Done to Prevent Heat-Related Illnesses?

    • Drink plenty of fluids during hot weather.
    • Avoid caffeine or alcoholic beverages, as they make the body lose water and increase the risk of heat illnesses.
    • Wear light, loose-fitting, breathable clothing, such as clothing made from cotton.
    • Take short, frequent breaks in areas out of the way from the heat.
    • Use fans or other methods of creating airflow, such as exhaust ventilation or air blowers.

Drink Water!
In the course of a day's work in the heat, a worker may produce as much as 2 to 3 gallons of sweat. Because so many heat disorders involve excessive dehydration of the body, it is essential that water intake during the workday be about equal to the amount of sweat produced. Most workers exposed to hot conditions drink less fluids than needed because of an insufficient thirst drive. A worker, therefore, should not depend on thirst to signal when and how much to drink. Instead, the worker should drink 5 to 7 ounces of fluids every 15 to 20 minutes to replenish the necessary fluids in the body.

Do Not Take Salt Tablets!
Heat acclimatized workers lose much less salt in their sweat than do workers who are not adjusted to the heat. The average American diet contains sufficient salt for acclimatized workers even when sweat production is high. If, for some reason, salt replacement is required, the best way to compensate for the loss is to add a little extra salt to the food. Salt tablets should not be used.