Dehydration and Heat Illness in Children

Medically Reviewed by Amita Shroff, MD on June 14, 2021

Children are more prone to dehydration and heat illness than adults because they have more body surface area per pound of weight. Young athletes, practicing hard in the summer heat, are at particular risk. Learn to recognize the early warning signs of heat stress. Your knowledge could save a child's life.

Symptoms of dehydration in children can include:

  • Thirst
  • Fatigue
  • Irritability
  • Dry mouth
  • Feeling hot

When children complain of thirst, feeling hot, or just seem irritable in the heat, they may have early dehydration. Get the child out of the sun into a cool, comfortable place. Have them start drinking plenty of cool fluids such as water or sports drinks. Sugary fruit juices or sodas with more than 8% carbohydrates are not recommended, because it is not absorbed as rapidly by the body. They should also take off any excess layers of clothing or bulky sports equipment. You can put cool, wet cloths on overheated skin.

If these symptoms are ignored, more serious heat illness such as heat exhaustion or heatstroke can occur.

  • Heat cramps: Painful cramps of the abdominal muscles, arms, or legs.
  • Heat syncope: Weakness, fatigue, or fainting after exercising in heat.
  • Heat exhaustion: Profuse sweating, fatigue, headache, dizziness, loss of appetite, nausea, vomiting, chills, weakness, excessive thirst, muscle aches and cramps, vision problems, flushing, agitation or irritability, and sometimes unconsciousness.
  • Heatstroke: High body temperature (often it's 104 F-105 F or higher), nausea and vomiting; seizures; disorientation or delirium; hot, dry skin; unconsciousness; coma; shortness of breath; decreased urination; or blood in urine or stool.

Note that there are other illnesses that can occur when exposed to the heat, such as prickly heat (heat rash) or heat edema (swelling of the arms and legs), but those are not associated with dehydration.

There is a lot you can do for a child experiencing symptoms of a heat illness related to dehydration. First, call for help. Next, take the child to a cool, shady place and encourage them to drink plenty of liquids. If they are experiencing a milder heat illness, rest and rehydration with water or a sports drink may be all that's needed. More severe heat illnesses require immediate medical attention.

Heat cramps. Heat cramps are one of the mildest forms of heat illness. When a young athlete experiences heat cramps, pull them off the field into a cool area and gently stretch the affected muscle.

"Have them drink, drink, drink, and then drink more," says Albert C. Hergenroeder, professor of pediatrics at Baylor College of Medicine and chief of the sports medicine clinic at Texas Children's Hospital.

"High-sodium drinks will prevent children from getting heat cramps," says Jackie Berning, PhD, with the National Alliance for Youth Sports. "Gatorade has just enough sodium to prevent those cramps. But if you're a heavy sweater, and you're still getting cramps after drinking Gatorade, eat some salted pretzels or salted nuts. Those work fine." If the cramp goes away, the child can go back out to the game or practice but should be carefully monitored.

Heat syncope. Heat syncope is an episode of near fainting with dizziness that occurs with prolonged standing or after suddenly rising from a lying or sitting position. In severe instances, the child may lose consciousness. People who exercise without a cool-down period, are dehydrated, or aren't acclimatized to the hot conditions, are more likely to experience this problem. Treatment consists of lying the person down and giving fluids if possible. If the person is unconscious or not able to drink, seek medical attention immediately.

Heat exhaustion. Heat exhaustion requires immediate attention. Symptoms include dizziness, nausea, vomiting, headaches, weakness, profuse sweating, excessive thirst, muscle aches and cramps, agitation or irritability, and sometimes unconsciousness. "This is a child who looks really wiped out and has symptoms of a clear problem to the casual observer, but her temperature is still less than 104," says Hergenroeder. Heat exhaustion requires immediate attention but is not usually life-threatening. However, in some cases, heat exhaustion can lead to heatstroke, which requires emergency medical treatment.

Just as with heat cramps, a child with heat exhaustion should be brought to a cool place and given plenty of fluids. The child should not be allowed to play or practice again that day. If they are becoming unconscious or confused, has a seizure, difficulty breathing, vomiting, or diarrhea, seek medical attention immediately.

Heatstroke. Heatstroke is also a medical emergency. Heatstroke is characterized by a high body temperature (often it's 104°F-105°F or higher) and marked symptoms, including nausea and vomiting; seizures; disorientation or delirium; hot, dry skin (although in some cases a person with heatstroke has profuse sweating); unconsciousness; coma; shortness of breath; decreased urination; or blood in urine or stool. It can occur suddenly, without any symptoms of heat exhaustion. "A child with heatstroke is going to the emergency room immediately, packed in ice, with IV fluids," says Hergenroeder.

For a child with heatstroke, cool the body while awaiting the ambulance by removing clothing and placing ice bags on the neck, in the armpits, and the groin areas. Fan the person and spray with cool water. If they are awake and able to swallow, give fluids.

Show Sources


Albert C. Hergenroeder, professor of pediatrics, Baylor College of Medicine; chief, the sports medicine clinic, Texas Children's Hospital.

Jackie Berning, PhD, National Alliance for Youth Sports.

Heat-Related Illness. American Family Physician, Sept. 1, 1998.

WebMD Medical Reference from Healthwise: Heat-Related Illness.

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