Heat exhaustion is a condition causing heavy sweating and a rapid pulse, a result of your body’s core temperature overheating. It's one of three heat-related syndromes, with heat cramps being the mildest and heatstroke being the most severe.

Causes of heat exhaustion include exposure to high temperatures with high humidity usually during strenuous physical activity. Without prompt treatment, heat exhaustion can lead to heatstroke. Fortunately, heat exhaustion is preventable.

There are precautions to prevent heat exhaustion. When temperatures climb, remember to:

• Wear loosefitting, lightweight, light-colored clothing. Excess, dark or tight clothing holds in heat and doesn't let your body cool properly because it inhibits sweat evaporation.
• Avoid sun directly on your skin. If you're going to be outdoors, wear a lightweight, wide-brimmed hat or use an umbrella to protect yourself from the sun, and apply sunscreen to exposed skin.
• Seek a cooler place. Being in an air-conditioned building, even for just a few hours, is one of the best ways to prevent heat exhaustion. At the least, find a well-shaded spot.
• Drink plenty of fluids. Staying hydrated will help your body sweat and maintain a normal body temperature. If your doctor has told you to limit fluids because of a health condition, be sure to check with him or her about how much extra you need to drink when the temperature rises. Avoid alcoholic beverages.
• Take extra precautions with certain medications. Ask your doctor or pharmacist whether the medications you take make you more susceptible to heat exhaustion and, if so, what you can do to keep your body from overheating.
• Avoid hot areas or cool them down. Let your car cool off before you drive away. Never leave children or pets in a parked car for any period of time.

Know the signs of heat exhaustion:

Cool, moist skin when in the heat

Heavy sweating

Faint

Dizzy

Fatigue

Weak, rapid pulse

Low blood pressure when standing

Muscle cramps

Nausea

Headache

TREAT it:

If you notice the signs of heat exhaustion – immediately administer the following steps:

• Rest in a cool place. An air-conditioned building is the best, but at the least, find a shady spot. Rest on your back with your legs elevated higher than your heart level.
• Drink fluids. Stick to water or sports drinks. And not drinks that are too cold. Don't drink any alcoholic beverages, which can contribute to dehydration.
• Apply cool water to your skin. Take a cool shower or soak in a cool bath. Don't use alcohol on your skin which can dehydrate it.
• Loosen clothing. Remove any unnecessary clothing and make sure your clothes are lightweight and nonbinding.

If you don't begin to feel better within one hour, seek prompt medical attention.