From Tech Transfer Newsletter, Summer 2004 » printer-friendly

Staying Healthy in the Work Zone:
Working in the Heat

Working with heavy equipment in a tight space close to moving traffic may be a more obvious hazard to your safety, but the heat can be equally as dangerous. Too much heat can make you tired, hurt your job performance, increase your chance of injury-even kill you. Road crews often work outdoors in high temperatures, under full sun, in high humidity, and with light or no wind while wearing heavy or restrictive protective gear and laboring under intense physical exertion-the perfect combination for heat-related illnesses to strike.

Road crew workers need to know how to protect themselves from heat-related illnesses, how to recognize the symptoms in themselves and others, and how to respond if someone else on the crew suffers from a heat-related illness.

Heat-Related Illnesses

When you work in a hot environment and your body temperature increases, it attempts to maintain its normal temperature, transferring heat back into the environment by sweating. The hotter it gets around you, the harder your body works to stay cool; when it has absorbed more heat than it can naturally dissipate, and it can't keep up, heat related illnesses can strike. Heat related illnesses can range from mild prickly heat, muscle cramps and swelling, to severe heat exhaustion and heat stroke.

Prevention

• Drink up. Before work begins, drink water until you feel full. Then, as often as every 15 minutes, drink another cup (5 to 7 ounces) of water, fruit juice or sports drink. Keep drinking all day.
• Rest often. Cool down by resting in a cool, shady spot or an air conditioned space, if possible. Taking a rest and decreasing your level of exertion, will help cool you down. If you are working in protective clothing, you may need even more rest breaks.
• Keep you shirt on. Wear light-colored, loose-fitting, breathable clothing, if the work rules allow. Sweat soaked clothes cool you better than your bare skin. Choose and use the hard-hat with the widest brim. (And, don't forget to use sunscreen.)
• Skip the salt. Don't use salt tablets: they keep fluids in your stomach longer, leaving less fluid available for necessary sweat production. Your body requires even more water to get rid of the extra salt, increasing the amount of work your kidneys must do, and raising the risks of dehydration and high blood pressure.
• Work smarter. Encourage your boss to plan the job so that the heaviest work is done during the coolest time of day. Work in the shade whenever possible; a simple awning or canopy blocking the sun will go a long way toward keeping you cooler.
• Treat yourself right. Sufficient sleep and good nutrition are important for maintaining a high level of heat tolerance. Eat smaller meals before work activity. Avoid caffeine, alcohol and large amounts of sugar.

Gradual exposure to heat gives the body time to become more accustomed to higher environmental temperatures. Heat related illnesses are more likely to strike workers who have been away from hot environments and have become accustomed to lower temperatures, such as those returning to work following a vacation in a cooler climate, an extended illness, or indoor work duty. Workers who have otherwise not had time to adjust to the heat, such as those working during a sudden heat wave, also face greater risk.

Many conditions, medications and diseases interfere with the body's ability to regulate temperature and get rid of heat. Anyone taking medications (over-the-counter or by prescription) or suffering from a chronic illness or disease should consult a health professional to learn more about their risk for heat-related illnesses. Workers who may be at a greater risk of heat illnesses are the obese, the recently ill, and older individuals. Tobacco use and alcohol or drug abuse and withdrawal can interfere with the body's ability to cool itself.

Signs, Symptoms and Treatment

Home treatment is usually all that is needed to treat a mild heat-related illness. Heat rash can be treated with antihistamines, to relieve the swelling and itching, as long as no other heat-related symptoms are present. Heat cramps are treated by getting out of the heat and replacing fluids and salt with a rehydration or sports drink (but not with salt tablets, see more on salt tablets above). Swelling is treated with rest and by elevating the legs. Fainting usually doesn't last long; once the person lies down flat, preferably in a cooler location, the condition usually improves.

The first warning signs of more severe heat stress are sluggishness and a foggy feeling. The condition worsens as the body loses fluids through sweat. Cramps, dizziness, and fainting follow, leading to the most severe heat-induced illnesses: heat exhaustion and heat stroke.

Recognize the symptoms of heat exhaustion: excessive sweating; pale, cool, moist, clammy skin; headache; fatigue; blurred vision; feeling faint, lightheaded, dizzy or weak; mood change such as irritability, confusion, restlessness or anxiety; nausea or vomiting; decreased or dark colored urine; and fast heart rate and breathing.

Treat heat exhaustion by moving the victim to a cool place, in the shade or indoors. Apply cool, wet cloths and fan the victim, but stop if the person develops goose bumps or shivers. Rehydrate slowly with about one-half cup of water every 15 minutes. Total rehydration with oral fluids usually takes about 36 hours, but most people begin to feel better within a few hours and should rest at least 24 hours.

If left untreated, heat exhaustion could progress to heat stroke and possible death. Heat stroke causes severe dehydration and can cause body organs to stop functioning. Heat stroke 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.

Recognize the symptoms of heat stroke: dry, pale skin with no sweating; hot, red, dry skin that looks sunburned; mood changes such as irritability, confusion, restlessness or anxiety; seizures; and unconsciousness for longer than a minute.

Any person with symptoms of heat stroke requires immediate hospitalization. Call for help, then cool the person as quickly as possible by whatever means possible. While waiting for the ambulance to arrive, move the victim into the shade or air conditioning, soak the victim's clothing with water and vigorously fan the body to increase the cooling effect. If the person is awake and alert enough to swallow, give the person fluids for hydration.

References

Coping with Summer Heat.
The Road Ahead, Virginia Transportation Technology Transfer Center: June 2002.

Heat Stress in Construction: Hazard Alert. (pdf, 11k)
Center to Protect Workers Rights, Building and Construction Trades Department, AFL-CIO: 1996.
Go to www.cpwr.com/hazardalert.htm then click on "Heat Stress."

Heat-Related Illnesses. (html, 32k)
Health Encyclopedia, Healthwise, Incorporated, Kaiser Permanente: 2004.
Go to http://members.kaiserpermanente.org/kpweb/healthency/entrypage.do then click on "H" then "Heat-Related Illnesses."

OSHA Fact Sheet: Working Outdoors. (pdf, 75k)
Occupational Safety and Health Administration, US Department of Labor: 2003.
Go to www.osha.gov then select "F" from the Site Index, click on "Factsheets" then "Working Outdoors."

Working in Hot Environments.
National Institute for Occupational Health and Safety, US Department of Health and Human Services: 1992.
Available at www.cdc.gov/niosh/hotenvt.html.

Working Under the Sun: A Catch-22 for Road Workers.
International Slurry Surfacing Association, Moving Forward, Pennsylvania Local Roads Program: Summer 2003.

Suggested Videos

Basic First Aid
The Training Network, 1994,
13 minutes, VH-540

Heat Stress for Construction
The Training Network, 1996,
17 minutes, VH-541

Health Hazards for Highway Construction
Associated General Contractors of America, 1999,
16 minutes, VH-573

Avoid Hot Mix Hazards: Working Safely with Hot Mix
Associated General Contractors of America, 1993,
15 minutes, VH-645

Thanks to LTAP funding, these and other materials are loaned from the Transportation Library at no charge to employees of California's local, state and regional transportation agencies. Requests must be made in writing by fax 510.642.9180 or e-mail itslib@berkeley.edu; the browsable catalog and request form are available on the Tech Transfer website www.techtransfer.berkeley.edu/videos/.

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