MONDAY, July 5 (HealthDay News) -- Extreme summer heat can be more than uncomfortable, it can be deadly.

Since 1979, about 8,000 Americans have died from heat exposure, according to the U.S. Centers for Disease Control and Prevention. Those most susceptible to extreme heat include the elderly and the very young, people with chronic diseases or mental illness, and those taking diuretics or blood pressure medications.

But young and healthy people are also at risk if they do physically strenuous activities in hot weather, according to researchers.

There are a number of ways to prevent overheating and protect yourself and others from heat exhaustion and heat stroke, said Dr. Larry Mellick of the emergency department at MCGHealth, an academic medical center of the Medical College of Georgia in Augusta:

• Schedule outdoor activities for early morning or early evening.
• Take regular breaks in shady areas or indoors so that your body's thermostat has a chance to recover.
• Avoid direct sunlight whenever possible. Always use sunscreen to reduce the heat your body absorbs and to limit moisture loss. Wear lightweight, light-colored, loose-fitting clothing and a wide-brimmed hat. People who work in the sun should take frequent breaks and not push themselves too hard.
• Drink plenty of fluids and don't wait until you're thirsty to drink. If you're doing heavy exercise in the heat, drink two to four glasses of cool fluids each hour. Even when you're swimming, you need to drink plenty of water.
• Don't eat a heavy or hot meal before going outside in hot weather. Doing so will heat your body faster.
• Avoid liquids that contain alcohol or large amounts of sugar -- they may cause you to lose more body fluids.
• If you're not used to exercising in hot weather, begin slowly and gradually increase your pace. If your heart starts to pound and you're gasping for breath, stop your activity, find a cool or shady area and rest.
• During hot weather, monitor the condition of family, friends and co-workers, and have someone do the same for you. During a heat wave, relatives and friends should call elderly people twice a day to ask how they're doing.
• If you have air conditioning, try to stay inside. If you don't have air conditioning, go to a public place that does have it. If you don't have air conditioning and can't leave your home, a cool shower or bath can help keep your body temperature cool.
• If you don't have air conditioning, avoid running the stove or oven on hot days.
• Call 911 immediately if you suspect that you or someone else has had a heat stroke, marked by a high body temperature, a rapid pulse, dizziness, confusion, fatigue, headache, seizure and/or hot, dry skin that is flushed but not sweaty.

More information

The U.S. Centers for Disease Control and Prevention has more about preventing heat-related illnesses.