Heat exhaustion is a condition that develops during prolonged exposure to heat. It's more likely to occur during strenuous activity, such as exercise or manual labor. Symptoms include a fast heartbeat, excess sweating, extreme tiredness, muscle cramps, headache, and weakness. They may also include stomach cramps, nausea, and vomiting. The person may be lightheaded and dizzy, and may even faint.
Treatment for heat exhaustion involves cooling the body down and replacing lost fluids, electrolytes, and salts. Cooling may be done with fans, cool cloths, or a cool-water bath. Fluids are best replaced by drinking chilled electrolyte solution, a sports drink, or water. If a person is very dehydrated, confused, or unable to drink, they will likely need IV (intravenous) fluids.
Heat exhaustion can progress to a serious condition called heatstroke, so it should be treated right away. The main difference between heat exhaustion and heat stroke is that during heat exhaustion the body is still able to sweat to try to cool down. Once the body loses the ability to sweat, the life-threatening emergency of heat stroke begins.
Continue to drink extra chilled fluids at home during the next 12 to 24 hours. Water, electrolyte solution, or sports drinks are advised. Don't drink alcohol or caffeine.
Preventing heat illness
Protect yourself from the heat. Wear lightweight, light-colored clothing and a broad-brimmed hat.
Drink plenty of fluids before and during activity.
Limit exercise in hot or very humid weather. If you have to be active in the heat, take frequent breaks to drink fluids and cool down.
Don't exercise when you are feeling ill.
Watch for symptoms of heat illness such as exhaustion, excessive sweating, and lightheadedness. If any occur, move to a cool place, rest, and drink cool fluids. Lying down with your legs raised slightly can help you recover.
Don't drink alcohol or caffeine.
Follow up with your healthcare provider, or as advised.
When to seek medical advice
Call your healthcare provider right away if any of these occur:
Call 911 for any of these symptoms of heatstroke: