Heat-related Illnesses

What are heat-related illnesses?

Exposure to abnormal or prolonged amounts of heat and humidity without relief or adequate fluid intake can cause various types of heat-related illness. Children and adolescents adjust more slowly than adults do to changes in environmental heat. They also produce more heat with activity than adults, and sweat less. Sweating is one of the body's normal cooling mechanisms. Children and adolescents often do not think to rest when having fun and may not drink enough fluids when playing, exercising, or participating in sports.

Children and adolescents with chronic health problems, or those who take certain medicines, may be more susceptible to heat-related illnesses. Children and adolescents who are overweight or wear heavy clothing during exertion, such as marching band or football uniforms, are also more susceptible.

There are three types of heat-related illnesses:

  • Exercise-associated muscle cramps

  • Heat exhaustion

  • Heat stroke

What are exercise-associated muscle cramps?

Exercise-associated muscle cramps are the mildest form of heat injury and consist of painful muscle cramps and spasms that occur during or after intense exercise and sweating in high heat.

What is heat exhaustion?

Heat exhaustion is more severe than exercise-associated muscle cramps and results from a loss of water and salt in the body. It occurs in conditions of extreme heat and excessive sweating without adequate fluid and salt replacement. Heat exhaustion occurs when the body is unable to cool itself properly and, if left untreated, can progress to heat stroke.

What is heat stroke?

Heat stroke, the most severe form of heat illness, occurs when the body's heat-regulating system is overwhelmed by excessive heat. It is a life-threatening emergency and requires immediate medical attention.

Symptoms and first-aid measures for heat injuries

The following chart contains the most common symptoms of heat-related injuries. However, each child may experience symptoms differently. In addition specific treatment will be determined by your child's primary care provider and may include some, or more, of the following:



First-aid and treatment

Exercise-associated muscle cramps

  • Painful cramps, especially in the legs

  • Flushed, moist skin

  • Move to a cool place and rest.

  • Give cool sports drinks containing salt and sugar, such as Gatorade.
  • Relax and stretch cramped muscles slowly and gently.

Heat exhaustion

  • Muscle cramps

  • Pale, moist skin (sweating)

  • Usually has a fever over 100.4° F (or 38° C)

  • Nausea

  • Vomiting

  • Diarrhea

  • Abdominal cramps

  • Headache

  • Fatigue

  • Weakness

  • Dizziness or lightheadedness

  • Move to a cool place and rest.

  • Lie down and elevate feet above head level

  • Give cool sports drinks containing salt and sugar, such as Gatorade.

  • If no improvement or unable to take fluids, call your child's primary care provider or take your child to an emergency department immediately. IV (intravenous) fluids may be needed.

Heat stroke

  • Warm, dry skin or sweating

  • High fever, usually over 104° F (or 38° C)

  • Rapid heart rate

  • Loss of appetite

  • Nausea

  • Vomiting

  • Headache

  • Fatigue

  • Confusion

  • Agitation

  • Hallucinations

  • Lethargy

  • Stupor

  • Seizures, coma, and death are possible

  • Call 911 or your local emergency medical service. Heat stroke is a life-threatening medical emergency and needs to be treated by a primary care provider.

  • Move to a cool place and rest.

  • Remove excess clothing and drench skin with ice water or cold water; fan skin.

  • Place ice bags on the neck, armpits and groin areas.

  • Offer cool fluids if alert and able to drink.

How can heat stroke be prevented?

Some general guidelines to help protect your child from heat-related illnesses include the following:

  • Drink plenty of fluids before and during vigorous or outdoor activities (including sunbathing), especially on hot days. Drinks of choice include water and sports drinks; avoid alcohol and fluids with caffeine, such as tea, coffee, and soda, as these can lead to dehydration.

  • Make sure your child dresses in light colored, lightweight, tightly-woven, loose-fitting clothing on hot days.

  • Schedule vigorous activity and sports for cooler times of the day. Take rest periods in shady or cool areas.

  • Makes sure your child is protected from the sun and wears a hat and sunglasses, and uses an umbrella. Use a sunscreen that is at least SPF (sun protection factor) 15 and reapply at least every two hours.

  • Increase time spent outdoors gradually to get your child's body used to the heat.

  • Teach children to take frequent drink breaks and "wet down" or mist themselves with a spray bottle to avoid becoming overheated.

  • Try to spend as much time indoors as possible on very hot and humid days.

  • Teach your child to warm up before and cool down and after exercising.

  • If your child has a medical condition or is taking medication, consult your child's primary care provider for further advice for preventing heat-related illnesses.

Reviewed by Zarana R. Swarup, MD, FAAP

Next Steps
Mother and daughter talking


With our patient portal you can schedule appointments, access records, see test results, ask your care provider questions, and more.

Boy getting height measured

Subscribe to Health Tips

Subscribe to our Health Tips enewsletter to receive health and wellness tips from the pediatric experts at CHOP.