Heat Exhaustion, First Aid

Who's At Risk?

People most susceptible to heat exhaustion are those outdoors on a hot, humid day or those inside in a poorly ventilated area, particularly children, older adults, or people who are overweight. Children and older adults may experience the fastest progression of symptoms and can collapse suddenly.

Certain medications can make people more susceptible to heat illness because medications may alter the way the body handles heat and sun.

People who drink alcohol before, during, or after vigorous activity are more susceptible to heat illness, as are people who work or exercise excessively, coupled with profuse perspiration and inadequate fluid intake.

Even people in excellent health can experience heat illness if early symptoms are ignored.

Signs & Symptoms

A person with heat exhaustion may feel faint or nauseated, be very thirsty, act irrationally, have dilated pupils (pupils larger than normal), be very sweaty, or have cool and moist skin that is either red or paler than usual.

You can differentiate the moderately severe form of heat illness, heat exhaustion, from more severe or less severe forms by comparing the person’s symptoms described above to the following:

• Heat cramps include painful muscle cramps (eg, in the legs, arms, abdomen, or back), heavy perspiration, and general weakness / lightheadedness.
• Heatstroke includes some or all of the following symptoms:
  • A high body temperature (above 102°F [38.9°C])
  • Skin that is red and hot with lack of sweating (sweating has stopped)
  • Small pupils
  • A rapid, weak pulse
  • Rapid, shallow breathing
  • Extreme confusion or irritability
  • Weakness
  • Seizures
  • Unconsciousness

Self-Care Guidelines

First Aid Guide
Use a combination of the following measures, depending on the circumstances and means available:

• Have the person rest, legs slightly elevated, in a shaded area or in a cool or air-conditioned building, room, or car.
• Remove or loosen the person’s clothes.
• Give the person an electrolyte drink (eg, Gatorade or Pedialyte), clear juice, or water. Do not give beverages that contain caffeine or alcohol. Note: You can make a salted drink by adding 1 teaspoon of salt to 1 quart of water.
• If the person is alert, pour water over them or spray them with a hose.
• Wrap the person in wet cloth and position a fan toward them. Evaporation of water on the skin aids in cooling.
• Apply cold compresses (eg, to the neck, armpits, groin).
• Avoid strenuous activity for a few hours.

If possible, take the person’s temperature while starting cooling measures and continue to check their temperature every few minutes. Once it has gone down to 100°F (37.8°C), you can discontinue cooling measures, but continue to check the person’s temperature every 30 minutes for a few hours to ensure it stays down.

Treatments

The medical professional will aim to cool the patient down in a controlled fashion, while ensuring they stay hydrated and have normal blood flow.

The medical professional will rehydrate the person gradually as needed by either giving an electrolyte drink or intravenous fluids.

Visit Urgency

If you suspect heatstroke, if there is no improvement with the above self-care measures after an hour, if symptoms worsen, or if there are signs of shock, seizure, or loss of consciousness, seek emergency medical care.

Trusted Links

• MedlinePlus: Heat Illness