Playing outside, practicing a sport, or spending time at the pool can be plenty of fun. But when temperatures are high in the summer, the body has to work harder to stay cool. If the body cannot get rid of heat quickly enough, a child can develop a heat-related illness.
Heat illness is not just one condition. It is a spectrum ranging from relatively mild problems such as heat rash and heat cramps to heat stroke, a life-threatening emergency. Understanding the warning signs can help students, parents, coaches, and teachers recognize heat illness before it becomes dangerous.
Children can be particularly vulnerable to heat illness. Infants and young children have immature systems that are not adequate for regulating body temperature properly, and older children and teenagers may spend long periods exercising outdoors without realizing how much heat their bodies are accumulating. Young athletes have another important risk: they may push themselves to keep up with teammates or may hesitate to tell a coach that they feel sick. Sports such as football, soccer, running, and marching band can involve prolonged physical activity in hot and humid conditions.
The American Academy of Pediatrics emphasizes that healthy children and adolescents can participate safely in sports in hot weather when they are properly prepared, hydrated, allowed adequate recovery time, and monitored appropriately. Risk increases with dehydration, excessive exertion, inadequate rest, heavy uniforms or protective equipment, and insufficient acclimatization to the heat.
Types of Heat-Related Illnesses
Heat rash, sometimes called prickly heat, occurs when sweat ducts become blocked. It can cause small red bumps or blisters on the skin, usually in areas where clothing traps heat and moisture. Moving to a cooler environment, keeping the skin dry, and wearing loose clothing can help.
Heat cramps are painful muscle spasms that can occur after prolonged physical activity and heavy sweating. Heat cramps are often associated with loss of water and electrolytes from the body. Heat cramps are painful muscle spasms that can occur after heavy sweating and physical activity. Someone experiencing cramps can stop exercising, move to a cool place, and drink fluids if they are alert and able to drink.
Heat syncope is feeling dizzy or fainting from heat exposure. It can occur when the blood vessels in the skin become wider to release heat more easily, which causes blood to pool in the extremities and temporarily reduce blood flow to the brain. A child who becomes dizzy or faints should stop activity and move or be moved to a cool environment.
Heat exhaustion is more serious. Symptoms can include heavy sweating, weakness or abnormal fatigue, headaches, dizziness, nausea or vomiting, muscle cramps, faster heartbeat, and rapid breathing. If a child is experiencing these symptoms, they should immediately stop physical activity and move into a shaded or air-conditioned environment. Extra clothing should be removed and the child should be cooled. Heat exhaustion can progress rapidly, so it is important children are monitored closely.
Heat stroke is the most dangerous form of heat illness. It happens when the body’s ability to regulate its temperature fails. Usually, heat stroke is defined as core body temperature being above around 104°F (40°C) and altered mental function. The most important warning sign for heat stroke is a change in mental status. A child may become confused, irritable, sleepy, agitated, behave abnormally, have trouble walking, experience seizures, or lose consciousness. Other symptoms may include high body temperature, rapid heartbeat and breathing, headaches, nausea, weakness, flushed skin, and confusion.
Two Types of Heat Stroke
Exertional heat stroke generally affects otherwise healthy young people who participate in strenuous physical activity for prolonged periods in a hot environment. High school athletes are particularly notable because symptoms can develop suddenly during intense exercise.
Classic or nonexertional heat stroke is more likely during prolonged heat waves and can affect people who cannot adequately control their environment and/or fluid intake. Infants and very young children are particularly vulnerable to this type of heat stroke.
If heat stroke is suspected:
- Stop physical activity.
- Move the child to a cool or shaded location.
- Remove excess clothing and equipment.
- Begin aggressive cooling immediately.
- Call emergency medical services.
- If appropriate and available, use cold-water immersion or other effective cooling methods.
- If the child is fully awake and able to swallow safely, fluids may be given, but a child with altered mental status should not be forced to drink.
Rapid cooling is especially important to treating heat stroke because the duration of hyperthermia is a big determinant of the child’s outcomes. Cold-water immersion is considered one of the most effective methods for rapidly lowering body temperature. If immersion is not practical, wetting the skin with water while using fans, applying ice packs to areas such as the neck, armpits, and groin, and removing excess clothing can help.
Importantly, acetaminophen (Tylenol) or ibuprofen should not be used as treatment for heat stroke. Heat stroke is not the same as a fever caused by an infection, and fever-reducing medicines do not correct the underlying problem.
Prevention is the most effective treatment for heat illness. Children doing activities outside should:
- Drink fluids regularly rather than waiting until they are thirsty
- Take frequent breaks in shade or air conditioning
- Wear lightweight, breathable clothing when possible
- Avoid unnecessary layers and heavy equipment during extreme heat
- Gradually become accustomed to exercising in hot weather
- Get adequate sleep and recovery between intense workouts
- Tell a coach, teacher, parent, or teammate immediately if they feel dizzy, weak, nauseated, confused, or unusually hot
- Never be afraid to stop exercising when something feels wrong
The AAP recommends that coaches, athletic trainers, teachers, and other adults supervising young athletes actively monitor children for warning signs such as dizziness, headache, unusual fatigue, vomiting, changes in personality or mental status, and declining athletic performance.
Heat illness is more than an uncomfortable summer problem. It can cause serious injury to the brain, kidneys, liver, and other organs. The nervous system is particularly sensitive to extreme temperatures, and severe heat stroke can cause permanent neurological injury or death. Heat-related deaths are also a significant public-health problem in the United States. According to the CDC, an average of 702 heat-related deaths occurred each year from 2004 through 2018, with about 90% occurring between May and September.
References
- American Academy of Pediatrics. Climatic Heat Stress and Exercising Children and Adolescents. Pediatrics. 2011;128(3). Reaffirmed 2019 and 2025. Read the AAP article
- Eifling KP, Gaudio F, Dumke C, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2024 Update. Wilderness & Environmental Medicine. 2024;35(1 Suppl):112S-127S. Read the 2024 guidelines
- Lipman GS, Gaudio F, Eifling K, et al. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2019 Update. Wilderness & Environmental Medicine. 2019;30(4S). Read the 2019 guidelines
- Vaidyanathan A, Malilay J, Schramm P, Saha S. Heat-Related Deaths — United States, 2004–2018. MMWR Morbidity and Mortality Weekly Report. 2020;69(24):729-734. Read the CDC article
- Lipman GS, Eifling KP, Ellis MA, et al. Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Heat-Related Illness: 2014 Update. Wilderness & Environmental Medicine. 2014;25(4 Suppl). Read the PubMed article