Diseases and Conditions

Heat exhaustion

Symptoms

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. If you are with someone showing signs of heat exhaustion, seek immediate medical attention if he or she becomes confused or agitated, loses consciousness, or is unable to drink. You will need immediate cooling and urgent medical attention if your core body temperature (measured by a rectal thermometer) reaches 104 F (40 C) or higher.