Armed Against the Heat

This is the ultimate "pay attention" hazard. If you don't prevent it, you'll pay attention when excessive exposure strikes your employees.

HEAT stress is occupational quicksand. By the time you realize you or your employees have a problem, it's too late! Heat-related problems often creep up on employees who may not realize the potential danger and be able to self-protect. It is up to the supervisor (and higher management) to ensure everyone knows the hazards and the approved precautions to safeguard everyone on the job site.

All of us have worked in hot conditions and suddenly started to feel weird, foggy, clammy. Too often, employees don't heed the warning signs and push on till they collapse. There's classic occupational heat in foundries, landscaping, cooking, construction work, warehouses, and kiln tending--only a small sample of the daily occupations that may be exposed.
Employees may not want to admit human frailty or fear teasing from others. New employees are often the worst, thinking it could jeopardize their chances at long-term employment if they are not "tough enough." Other heat stress situations are situational, such as one-time repairs, not watching the weather closely enough, a big office move, or specific maintenance activities in adverse conditions. Still others are related to employees' actions, such as heavy alcohol consumption off duty or not being used to the high heat upon return from vacation. High humidity, personal illness, fatigue, and medication change can make a difference from one day to the next.

Seasonal Issues
In the depths of winter we long for summer's sunny, bright days--until we work in it! Quick temperature transition is even harder on the human body, especially in late spring when the temperature swings dramatically from cool to hot within hours. Our bodies can adjust, but it takes time. Age and other health woes add to the adjustment time factor. The bad news is that so often we (or our employers) fail to take heat stress as potentially serious, overlook warning signs, and fail to plan ahead. Then we and they can become completely involved with a heat-related illness, seemingly unaware.

Now is a good time to remind everyone of the dangers of heat stress and what signs they should look for. Review with employees the following items to ensure safety of all full-time, temporary, or contract workers. Don't forget volunteers if your facility uses them. Education and training are critical for heat management. Make sure everyone at your facility has a basic heat awareness level and knows how to respond to others who are experiencing heat-caused problems. The higher the level of heat exposure (duration and temperature) would necessitate a greater level of knowledge and understanding of recognition and treatment.

Make sure adequate first aid and hydration are available, too.

* Know personal limitations. Most of us know whether we can tolerate the heat or not. Ask your employees so extra effort can be made to ensure good work conditions.
* Change work schedules when possible to the cooler part of the day. Or check the weather and watch for cooler temps, which will save wear and tear on employees.
* Make sure employees drink cool water (not ice water) in small amounts frequently. For example, have them drink one cup every 20-30 minutes and avoid alcohol, coffee, tea, and caffeinated soft drinks, which cause dehydration. Discourage high-energy drinks on the job that contain huge doses of caffeine and sugar because they can significantly increase body stress.
* Encourage employees to wear lightweight, light-colored, loose-fitting clothing such as natural fabrics or the new specially created cool fabrics.
* Check the weather often, especially the dew point and temperature. Provide short, frequent work-break times when it's hot.
* Discuss health risks with employees. Help them understand this is more than an employer being nosy, and that certain medical conditions can spell danger for employees (such as heart conditions, diabetes, and some medications can increase the risk of injury from heat exposure).
* Advise employees to avoid heavy meals while working in high heat situations.
* Provide good general ventilation and monitor its effectiveness. Make sure ventilation is not impairing the work being done.
* Check on employees often and monitor workplace temperature and humidity. Stay alert for any sign of heat-related illness. Allow employees to take a rest break if they become extremely uncomfortable without fear of losing their jobs. Have a pre-designated place for them to cool off.
* Ensure first aid is quickly available and that those who are designated responders can recognize and treat heat-related problems on site or refer to medical facilities quickly.
* Make sure each employee is physically and mentally fit to work in high heat situations. Work hardening can assist greatly as they acclimate.
Heat stress is the ultimate "pay attention" hazard. If you do not provide the adequate thought and prevention, you will pay attention when excessive exposure strikes your employees.

Health Problems of Hot Work Environments
Excessive exposure to a hot work environment can bring about a variety of heat-induced disorders.

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.
A heat stroke victim's skin is hot, usually dry, red, or spotted. Body temperature is usually 105 degrees F or higher, and the victim is mentally confused, delirious, perhaps in convulsions, or unconscious. 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, and vigorously fanning the body to increase cooling. Further treatment at a medical facility should be directed to the continuation of the cooling process and the monitoring of complications which often accompany the heat stroke. Early recognition and treatment of heat stroke are the only means of preventing permanent brain damage or 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. A worker suffering from heat exhaustion still sweats but experiences extreme weakness or fatigue, giddiness, nausea, or headache. In more serious cases, the victim may vomit or lose consciousness. The skin is clammy and moist, the complexion is pale or flushed, and the 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 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.

A worker who is not accustomed to hot environments and who stands erect and immobile in the heat may faint. With enlarged blood vessels in the skin and in the lower part of the body due to the body's attempts to control internal temperature, blood may pool there rather than return to the heart to be pumped to the brain. Upon lying down, the worker should soon recover. By moving around, and thereby preventing blood from pooling, the patient can prevent further fainting.

Heat Rash
Heat rash, also known as prickly heat, is likely to occur in hot, humid environments where sweat is not easily removed from the surface of the skin by evaporation and the skin remains wet most of the time. The sweat ducts become plugged, and a skin rash soon appears. When the rash is extensive or when it is complicated by infection, prickly heat can be very uncomfortable and may reduce a worker's performance. The worker can prevent this condition by resting in a cool place part of each day and by regularly bathing and drying the skin.

Transient Heat Fatigue
Transient heat fatigue refers to the temporary state of discomfort and mental or psychological strain arising from prolonged heat exposure. Workers unaccustomed to the heat are particularly susceptible and can suffer, to varying degrees, a decline in task performance, coordination, alertness, and vigilance. The severity of transient heat fatigue will be lessened by a period of gradual adjustment to the hot environment (heat acclimatization).


This article originally appeared in the May 2007 issue of Occupational Health & Safety.

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