It happens every summer: Overzealous fitness and nature enthusiasts ignore common sense guidelines and suffer heat-related illness they could have avoided.

Heat exhaustion kicks in when your body dehydrates due to sweat (fluid) loss with no fluid replacement. Symptoms include fatigue; weakness; dizziness; muscle cramps; nausea; and cool, clammy, pale, red or flushed skin. Move to a cooler environment to avoid further dehydration and drink a cold sports drink. Seek medical attention for serious cases.

Heat exhaustion can lead to heat stroke, which occurs when your body temperature keeps rising—often to 105 degrees or higher. Symptoms include confusion or unconsciousness, and hot, red or flushed skin (even under the armpits). Heat stroke is a life and death situation. Call 911 or seek emergency care if signs of heat stroke develop.

Keep in mind that muscle activity increases your internal heat production up to 10 times more during exercise than when resting. Your body compensates by sweating. If it’s 95 degrees outside with 90% humidity, your sweat can’t evaporate, and your body won’t cool down.

Follow these precautions:

• Drink plenty of water. You can lose up to two quarts of fluid per hour, so keep hydrated. Drink 16 ounces (about two glasses) before exercising. Continue to drink water during your workout; and 20 minutes after your workout, drink another 8 ounces. 
• Evaluate the shape you’re in before heading outdoors. Overweight people tend to generate more heat and more sweat—and thus need more fluid to function well. 
• Become familiar with weather reports and the heat index. Beware of exercising outdoors on days with high temperature coupled with high humidity. Avoid strenuous outdoor activities during the hottest part of the day.
• Wear light-colored, loose-fitting clothes with ventilation. Dark clothes absorb sunlight instead of reflecting it as light-colored clothes do. The ventilation helps to cool the body by aiding in the evaporation of sweat.
• Become acclimatized. Do short workouts outside until you become accustomed to the weather.
• Avoid salt tablets. Contrary to popular belief, salt tablets will make matters worse. They disrupt the absorption process of water, robbing your muscles of the water needed to function. Cramping will likely set in.
• Move your activities indoors. This is perhaps the best thing you can do to avoid heat-related illnesses. If you have to be outside, try to find as much shade as possible.