Heat Precautions for Outdoor Workers

The Houston Department of Health and Human Services (HDHHS) reminds employers that high heat can be a serious health hazard for outdoor workers.

Extreme heat can have a dramatic effect on an employees' comfort and potentially on their health. Please consider the following recommendations to protect the health of your employees who are required to work outdoors.

• Personal acclimatization to high temperatures is critical to an individual's ability to cope with high temperatures. Allow new employees several days to physically adjust to working in high temperature settings.
• Workers can lose up to two gallons of fluid a day, causing fatigue and other heat-related illnesses that result in reduced productivity and lost time. Most workers will drink less water than required because thirst is not an adequate indicator of how much essential fluid and electrolytes have been lost. Use electrolyte-replacement beverages when heat and heavy exertion can put workers in danger of dehydration. Workers should consume 16 to 32 ounces of cool fluids per hour when working outside. Very cold fluids can cause stomach cramps. Salt intake should occur with meals. Do not take salt tablets unless directed by a physician. Alcoholic beverages should never be consumed immediately before or during work in high heat. <
• The body's natural reaction to high heat is to slow down activity. Allow for frequent breaks in the shade or air conditioning.
• Some tasks can be accomplished at hours other than the hottest parts of the afternoon. Managers should consider restructuring the daily work load to accomplish the most strenuous tasks during the cooler mornings or evenings.
• Employees should be encouraged to wear light weight, loose fitting clothing. A brimmed hat will keep the head cooler and provide shade for the face and possibly neck.
• Sunburn will affect the body's ability to cool itself and causes a loss of body fluid. It also causes pain and damages the skin. Utilize a sunscreen with an SPF of 15 or higher. Follow label instructions.
• Managers should consider excluding from outdoor labor during high heat conditions the following people: anyone over the age of 55; people who are overweight; people with heart and respiratory problems; people with hypertension; people on medica- tions; people who are or have recently been ill.

High heat can cause the following illnesses:

Heat cramps usually affect people who sweat heavily during strenuous activity. Sweating depletes the body's salt and fluid. Heat cramps may also be a symptom of heat exhaustion. Heat cramps are muscle pains or spasms, usually in the abdomen, arms or legs, that may occur in association with strenuous activity. If the person has heart problems or is on a low sodium diet, medical attention is necessary.

If medical attention is not necessary, the individual should stop all activity and sit quietly in a cool, shady or air conditioned place. The individual should drink water, clear juice or a sports beverage. The person should not return to strenuous activity for a few hours after the cramp subsides because further exertion may lead to heat exhaustion or heat stroke. Seek medical attention for heat cramps if they do not subside in one hour.

Heat exhaustion is the body's response to an excessive loss of the water and salt contained in sweat. The most prone to heat exhaustion are the elderly, people with high blood pressure and people working or exercising in high heat. The symptoms of heat exhaustion include: heavy sweating, paleness, muscle cramps, fatigue, weakness, dizziness, headache, nausea or vomiting and fainting. The skin may be cool and moist. The victim's pulse rate will be fast and weak and breathing will be fast and shallow. If untreated, heat exhaustion may lead to heat stroke.

Medical attention should be sought if the symptoms are severe or the victim has heart problems or high blood pressure. Otherwise, help the victim to cool off and seek medical attention if the symptoms worsen or last longer than one hour. Cooling measures that may be effective include: cool, nonalcoholic beverages, rest, cool shower, bath or sponge bath, air conditioning and removal of heavy clothing.

Heat stroke occurs when the body becomes unable to control its temperature. The body's temperature rises rapidly, the sweating mechanism fails and the body is unable to cool down. Body temperature may rise to 106 degrees or higher in ten to 15 minutes. Heat stroke can cause death or permanent disability if emergency treatment is not given quickly. The victim is unlikely to complain due to the confusion caused by heat stroke therefore it is very important for managers and coworkers to notice if changes in mental status occur.

Warning signs of heat stroke vary but may include: body temperature above 103 degrees; red, hot and dry skin, no sweating; rapid, strong pulse; throbbing headache; dizziness; nausea; confusion; unconsciousness. If any of these symptoms occur, you may be dealing with a life-threatening emergency and should call 911 immediately.

Move the victim to a cool, shady place. Cool the victim rapidly using whatever means possible - cool water spray, cool shower, air conditioning. If possible, monitor the body temperature and continue cooling until it drops to 101-102 degrees. Do not give alcoholic beverages to drink. Sometimes a victim's muscles will begin to twitch uncontrollably as a result of heat stroke. If this happens, keep the victim from injuring himself, but do not place any object in the mouth and do not give fluids. If vomiting occurs, make sure the airway remains open by turning the victim on his or her side.

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©2006 Texas Medical Center

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