Heat exhaustion is a condition whose symptoms may include heavy sweating and a rapid pulse, a result of your body 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, particularly when combined with high humidity, and strenuous physical activity. Without prompt treatment, heat exhaustion can progress to heatstroke, a life-threatening condition. Fortunately, heat exhaustion is preventable.
Signs and symptoms of heat exhaustion may come on suddenly or may develop after days of heat exposure. Possible heat exhaustion signs and symptoms include:
When to see a doctor
Contact your doctor if your signs or symptoms worsen or if they don't improve within 60 minutes. Seek immediate medical attention if your body temperature reaches 104 F (40 C) or higher.
Your body's heat combined with environmental heat results in what's called your core temperature — your body's internal temperature. Your body needs to regulate the heat gain (and in cold weather, heat loss) from the environment to maintain a core temperature that's normal, approximately 98.6 F (37 C).
Impaired cooling mechanism
As a result, your body may develop heat cramps, the mildest form of heat-related illness. Signs and symptoms of heat cramps usually include heavy sweating, fatigue, thirst and muscle cramps. Prompt treatment usually prevents heat cramps from progressing to heat exhaustion.
You usually can treat heat cramps by drinking fluids containing electrolytes (such as Gatorade or other sports drinks), getting into cooler temperatures, such as an air-conditioned or shaded place, and resting.
Anyone can develop heat exhaustion, but certain factors increase your sensitivity to heat. They include:
Untreated, heat exhaustion can progress to heatstroke, a life-threatening condition that occurs when your body temperature reaches 104 F (40 C) or higher. Heatstroke requires immediate medical attention to prevent permanent damage to your brain and other vital organs that can result in death.
Treatments and drugs
In most cases, you can treat heat exhaustion yourself by doing the following:
If you don't begin to feel better within 60 minutes of using these treatment measures, seek prompt medical attention. You may be given intravenous (IV) fluids to help you rehydrate. Immersion in cold water, misting your skin, placing you in front of fans, or using cold or ice packs and cooling blankets are some of the techniques that may be used to bring down your body temperature.
You can take a number of precautions to prevent heat exhaustion and other heat-related illnesses. When temperatures climb, remember to:
It's best not to exercise or engage in any strenuous activity in hot weather, but if you must, follow the same precautions and rest frequently in a cool spot. Taking breaks and replenishing your fluids during that time will help your body regulate your temperature.
Last Updated: 2009-11-21
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