Heat exhaustion

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 lead to heatstroke, a life-threatening condition. Fortunately, heat exhaustion is preventable.

Symptoms Causes Risk factors Complications Prevention

Signs and symptoms of heat exhaustion may develop suddenly or over time, especially with prolonged periods of exercise. Possible heat exhaustion signs and symptoms include:

  • Cool, moist skin with goose bumps when in the heat
  • Heavy sweating
  • Faintness
  • Dizziness
  • Fatigue
  • Weak, rapid pulse
  • Low blood pressure upon standing
  • Muscle cramps
  • Nausea
  • Headache

When to see a doctor

If you think you're experiencing heat exhaustion:

  • Stop all activity and rest
  • Move to a cooler place
  • Drink cool water or sports drinks

Contact your doctor if your signs or symptoms worsen or if they don't improve within one hour. Seek immediate medical attention if your body temperature reaches 104 F (40 C) or higher.

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