Fitness & Exercise

Heat Exhaustion

Preventing Heat Exhaustion

When the heat index is high, it's best to stay inside in air conditioning. If you must go outdoors, you can prevent heat exhaustion by taking these steps:

• Wear lightweight, light-colored, loose-fitting clothing, and a wide-brimmed hat.
• Use a sunscreen with an SPF of 30 or more.
• Drink extra fluids. To prevent dehydration, it's generally recommended to drink at least eight glasses of water, fruit juice, or vegetable juice per day. Because heat-related illness also can result from salt depletion, it may be advisable to substitute an electrolyte-rich sports drink for water during periods of extreme heat and humidity.
• Take additional precautions when exercising or working outdoors. The general recommendation is to drink 24 ounces of fluid two hours before exercise, and consider adding another eight ounces of water or sports drink right before exercise. During exercise, you should consume another eight ounces of water every 20 minutes even if you don't feel thirsty.

Avoid fluids containing either caffeine or alcohol, because both substances can make you lose more fluids and worsen heat exhaustion. If you have epilepsy or heart, kidney, or liver disease; are on fluid-restricted diets; or have a problem with fluid retention, check with your doctor before increasing liquid intake.