Heat Illness Prevention

With summer approaching, we all need to be reminded about the hazards of heat illness. Heat illness (heat cramps, heat exhaustion, and heat stroke) occurs as a result of excessive heat stress from the environment. Every year we read about athletes and workers who experience heat illness some with serious health consequences. People are best able to manage heat stress when they are fully hydrated, physically fit, acclimatized, well nourished, and well rested. Personal protective equipment such as respirators, coveralls, and sports padding can significantly increase the risk of heat illness.

Those individuals who work or play outdoors should be instructed regarding preventive measures that would enable them to safely tolerate warmer temperatures. Outdoor workers and athletes may not have an opportunity to cool off in an air conditioned environment. Many different occupations are at risk for heat injuries such as: landscapers, farmers, roofers, street repair crews, painters, telephone crews, power line workers, cable installers, etc.

Hydration is the most important preventive measure to prevent heat illness. Adequate hydration is critical to the prevention of heat illness because it is essential to maintain blood volume for cooling the body and sweating to release body heat. Both are reduced by dehydration. Limiting water for drinking is never advised. Employers and coaches should assure that workers and athletes have easy access to adequate amounts of drinking water.

Many people do not realize the critical importance of preventive measures regarding heat illness, especially hydration. Even mild dehydration (2-3% of body weight) significantly reduces physical capacity and heat tolerance. As dehydration increases, thinking ability decreases. This may affect the quality of work, athletic performance, and lead to accidents. Avoiding heat casualties requires that employees and athletes drink enough water to replace what they lose. Once the thirst sensation is noted the body is already 1-2% dehydrated. Thus, people should be encouraged to drink water before they become thirsty. The list below provides specific recommendations to prevent heat illness.



1. Educate individuals about the hazards of heat stress illness.

2. Drink more fluids in a warm environment even if you are not active.

3. Active individuals may lose up to 3 gallons of sweat each day.

4. Active individuals should drink 5-7 ounces of fluid every 20 minutes in hot environments.

5. Do not wait until you are thirsty to drink.

6. Do not drink liquids that contain alcohol, caffeine, or large amounts of sugar.

7. Very cold drinks may cause stomach cramps.

8. Fans may provide comfort however heat illness can still occur.

9. Take rest breaks in air-conditioned spaces if possible.

10. Wear lightweight loose fitting clothing.

11. Protect yourself from the sun – wear a wide brim hat, sunglasses, and use sunscreen.

12. Perform strenuous work or exercise early in the morning or later at night if possible.

13. Decrease the amount and intensity of exercise in hot environments.

14. Allow individuals to gradually become accustomed to heat by modifying their activity.

15. Establish work – rest cycles to minimize heat stress.

16. Postpone nonessential activities in hot environments.

17. After an episode of heat illness that person is at higher risk for future heat illness.

18. Encourage workers and athletes to obtain sufficient sleep and maintain good nutrition.

19. Those at increased risk for heat illness are obese, chronically ill, and older individuals.

20. Certain medications may increase the risk of heat illness such as: diuretics, laxatives, allergy medicines, diet pills, amphetamines, and some blood pressure medicines. Check with your doctor if you have further questions.


Remember—Heat illness is preventable!

Don Herip, MD, MPH, FACOEM
Occupational Health
Baptist Medical Group