Summer means long days outside, sweaty practices, pool trips, and playground time. It also means heat, and for children, heat illness can become serious quickly.
Heat stroke is not simply a bad case of overheating. It is a life-threatening medical emergency that can cause permanent organ damage or death if it is not recognized and treated immediately.
This article is not meant to frighten you. It is meant to help you recognize the difference between a child who needs water, rest, and shade, and a child who needs emergency care.
In this article you will learn why children require extra monitoring in hot conditions, how to tell the difference between heat exhaustion and heat stroke, what to do during the critical first minutes, and how to reduce the risk of heat illness in the first place.
Why Children Need Extra Protection in the Heat
Children are not simply small adults when it comes to heat regulation. Their bodies differ from adults in several ways that can affect how they gain and release heat.
Children have a higher surface-area-to-body-mass ratio than adults. In moderate conditions, this may help them release heat through the skin. In very hot conditions, however, it can also cause them to absorb environmental heat more quickly.
Prepubertal children generally have lower sweat rates than adults because each sweat gland produces less sweat. They rely proportionally more on dry heat exchange through the skin. This can become disadvantageous when air temperature approaches or exceeds skin temperature or when humidity limits evaporation.
Research directly comparing heat strain in children and adults is complex, and not every study has found that children experience greater heat strain under the same conditions (1). Even so, children still require careful monitoring because they may not recognize symptoms, ask for water, reduce their activity, or leave a hot environment on their own.
Children should also be introduced gradually to exercise in hot weather. The first days of a hot season, a heat wave, or travel to a warmer climate deserve additional caution.
To learn more, read this article: Natural Treatment of Heat-Related Illnesses in Kids
The Spectrum of Heat Illness: From Heat Cramps to Heat Stroke
Heat illness exists on a spectrum. Understanding the signs of each stage can help you determine what action a child needs.
Heat Cramps
Heat cramps are painful muscle spasms, often in the legs or abdomen, that occur during or after physical activity in the heat. Fluid and electrolyte losses may contribute.
Move the child to a cool place, stop activity, and offer fluids if the child is fully alert and able to swallow normally. Persistent cramps, repeated vomiting, or worsening symptoms warrant medical advice.
Heat Exhaustion
Heat exhaustion occurs when the body is struggling to cope with heat and fluid loss.
Symptoms may include:
- Heavy sweating
- Pale or flushed skin
- Headache
- Dizziness or lightheadedness
- Weakness or unusual fatigue
- Nausea or vomiting
- Muscle cramps
- Fainting
A child with uncomplicated heat exhaustion should still be responsive and able to interact appropriately. Irritability, distress, or lightheadedness can occur, but clear confusion, seizure, collapse with abnormal responsiveness, marked disorientation, or loss of consciousness suggests heat stroke rather than simple heat exhaustion (2).
Move the child into air conditioning or shade, remove excess clothing and sports equipment, cool the skin with water and wet towels, and offer small sips of cool fluid if the child is fully alert and swallowing normally.
Seek urgent medical advice if symptoms are severe, do not improve promptly with cooling, or include repeated vomiting or fainting.
Heat Stroke
Heat stroke is the most severe form of heat illness and is a medical emergency.
It is characterized by central nervous system dysfunction associated with severe hyperthermia. Core temperature is often around or above 40°C (104°F), but a reading below 40°C does not rule out heat stroke, especially if cooling has already begun or the temperature was measured with a less accurate device (2).
Do not wait for a thermometer reading if a child develops confusion, seizure, collapse, or abnormal responsiveness after heat exposure.
There are two broad types:
Exertional heat stroke occurs during vigorous physical activity, often affecting athletes and active older children or teenagers.
Non-exertional (or classic) heat stroke occurs because of environmental exposure without vigorous activity. This may affect infants, toddlers, children left in vehicles, and children with certain health conditions.
Both forms can be life-threatening.
Recognizing the Signs of Heat Stroke in Children
The most important warning sign is a change in brain function or behavior after heat exposure.
Call 911 immediately if a child in or recently exposed to heat develops any of the following (2):
- Confusion or disorientation
- Unusual or irrational behavior
- Slurred speech or difficulty speaking
- Stumbling or loss of coordination
- A seizure
- Collapse
- Extreme drowsiness or difficulty waking
- Unresponsiveness or loss of consciousness
- Hallucinations or delirium
Other signs may include:
- Very high body temperature
- Hot or flushed skin
- Heavy sweating or in some cases little sweating
- Rapid heart rate
- Rapid breathing
- Severe headache
- Nausea or vomiting
A child with exertional heat stroke may still be sweating. The absence of sweating is not required for heat stroke.
What to Do if Heat Stroke is Suspected
Call 911 immediately and begin cooling the child while emergency help is on the way. Do not delay the emergency call to take a temperature, find special equipment, or transport the child yourself unless the dispatcher instructs you to do so.
1. Check responsiveness and breathing
If the child is not breathing normally, begin CPR and follow the emergency dispatcher’s instructions. Protect the airway. A child who is seizing, vomiting, or unconscious should not be placed in water unless capable helpers can continuously support the head and airway.
2. Move the child out of the heat
Move the child into shade, air conditioning, or the coolest nearby location. Remove unnecessary clothing and sports equipment.
3. Begin rapid cooling
For an older child or adolescent with suspected exertional heat stroke, cold-water immersion is generally the fastest practical cooling method when it can be performed safely (3). A trained sports program may use a tub specifically prepared for this purpose. In that organized setting, medical and athletic-training guidance emphasizes beginning effective cooling on site rather than waiting until hospital arrival.
For a parent or bystander, safe options depend on the child’s age, condition, available help, and the environment. Follow the emergency dispatcher’s instructions.
Possible cooling methods include:
- Placing an older, responsive child in a cool or cold bath while continuously supporting and monitoring them
- Using a cool shower
- Soaking the skin and clothing with cool water while fanning
- Applying cool, wet towels and replacing them frequently
- Applying wrapped cold packs near the neck, armpits, and groin
Never leave the child alone in a bathtub, pool, or other container. If immersion is not safe or practical, do not delay cooling. Wet the child thoroughly and fan continuously while waiting for EMS.
4. Do not give fever-reducing medicine
Do not give acetaminophen or ibuprofen for heat stroke. These medicines treat fever by changing the brain’s temperature set point. Heat stroke has a different mechanism, so fever-reducing medicine does not correct the problem and may add stress to injured organs.
5. Be careful with fluids
Do not give anything by mouth to a child who is confused, extremely drowsy, repeatedly vomiting, seizing, unconscious, or unable to swallow normally. A fully alert child who can swallow safely may take small sips of cool fluid, but oral hydration must never delay active cooling or emergency care.
Heat stroke requires medical evaluation because complications may include kidney injury, liver injury, muscle breakdown, abnormal clotting, and damage to the brain and other organs.
Special Heat Stroke Consideration: Infants and Young Children
Infants and toddlers depend entirely on adults to protect them from heat. They cannot move to a cooler place, remove clothing, ask for a drink, or clearly explain what they are feeling.
Warning signs after heat exposure may include:
- A very hot body
- Flushed or hot skin
- Unusual sleepiness, limpness, or weakness
- Extreme irritability
- Poor feeding
- Repeated vomiting
- Fewer wet diapers, which may indicate dehydration
- Difficulty waking
- Any change in responsiveness
An infant or toddler who is difficult to wake, limp, confused, seizing, or unresponsive after heat exposure needs immediate emergency care. Call 911 and begin cooling as directed. Move the child to a cool environment, remove excess clothing, wet the skin with cool water, and use gentle airflow. Avoid unsafe immersion when the child cannot keep their airway protected or when there is no capable adult to support them continuously.
Never overdress a baby in hot weather. Use lightweight clothing and avoid heavy blankets in warm environments. Check the baby’s chest or back rather than relying only on the hands and feet, which may feel cooler.
A note on strollers: Covering a stroller with a dry blanket or cloth to block the sun can reduce ventilation and trap heat. A 2023 study conducted in hot, moderately humid weather found that dry muslin and flannelette covers increased the temperature inside the stroller (4). Evaporative strategies performed better under the study conditions, particularly a moist muslin covering combined with fan-generated airflow. However, careful attention is still needed as a damp cloth can dry out and a fan can stop. Any covering can also make it harder to see the child.
The safest practical approach is to:
- Avoid tightly draping a dry blanket over the stroller
- Use the stroller’s ventilated canopy or another shade option that does not enclose the stroller
- Maintain airflow
- Keep the stroller out of direct sun whenever possible
- Check the child frequently
- Move indoors or into air conditioning during dangerous heat
Do not rely on a stroller fan alone during extreme heat. Fans become less useful as air temperature rises and should not replace air conditioning, shade, hydration, or frequent monitoring.
Special Heat Stroke Consideration: Teen Athletes
Teen athletes face a different pattern of heat risk. Exertional heat stroke can occur when an athlete is exercising hard in hot or humid conditions, especially while wearing helmets, pads, heavy uniforms, or other equipment that limits heat loss (5).
Risk may rise during:
- High-intensity conditioning
- The first practices of a hot season
- Sudden increases in workload
- Sessions without adequate rest or access to fluids
- Illness or recent fever
- Poor sleep
- Use of heavy protective equipment
- A previous episode of significant heat illness
Body size and conditioning
A larger body size and lower level of conditioning may increase the heat produced during exercise and make heat dissipation more difficult. These factors do not mean an athlete should be excluded, but they do signal a need for careful progression, rest breaks, and monitoring.
Sickle cell trait
Sickle cell trait is associated with a distinct risk of exertional sickling and collapse during intense exercise, particularly during demanding conditioning sessions. Heat, dehydration, altitude, and illness may increase risk. Exertional sickling is not the same condition as heat stroke, although the two can look similar during collapse. Athletes with known sickle cell trait should have an individualized participation and emergency plan developed with their healthcare and sports staff (5,6).
Medications
Some medicines may affect sweating, hydration, alertness, or cardiovascular responses in heat. These can include stimulant medicines, anticholinergic medicines, some antihistamines, and certain psychiatric medicines. Parents should not stop or change prescribed medications on their own. Ask the prescribing clinician whether a child needs additional precautions during exercise or extreme heat.
Previous heat illness
A child or teen who has experienced heat stroke requires medical clearance and a structured, supervised return to activity. A history of heat exhaustion should also be discussed with the child’s healthcare provider and coaching staff, particularly if the cause was unclear or symptoms were severe.
Heat acclimatization
Athletes should not move directly from relative inactivity into full-intensity practice in hot weather. A gradual 10 to 14 day progression is commonly recommended at the start of a hot season. Early sessions should be shorter and less intense, with equipment and workload added progressively (2). Coaches should also adjust activity according to environmental conditions, not only the clock.
The social culture of sport matters too. Athletes must be able to say “I don’t feel right” without punishment, embarrassment, or pressure to continue.
To learn more about supporting your teen athlete, read this article: How to Support Your Teen Athlete: Nutrition, Sleep, and Mental Health Tips for Parents
Hot Cars: A Preventable Cause of Pediatric Heat Stroke
Children should never be left alone in a parked vehicle, not even briefly and not even with the windows cracked. According to the National Highway Traffic Safety Administration, the temperature inside a vehicle can rise about 20°F in as little as 10 minutes (7). Heat stroke can occur even when the outside temperature is around 60°F. Cracking the windows or parking in the shade does not make it safe.
Children can also enter unlocked vehicles without an adult knowing. Keep parked vehicles locked and keep keys out of children’s reach.
Practical prevention habits include:
- Check the back seat every time you leave the vehicle
- Place a necessary item such as a bag or phone in the back seat as a reminder
- Set a childcare-arrival confirmation routine
- Ask childcare providers to call immediately if a child does not arrive as expected
- Keep vehicles locked when parked
- Call 911 immediately if you see a child alone in a vehicle
Heat Stroke Prevention: Practical Strategies for Families
Most pediatric heat illness can be prevented. Here is what matters most.
1. Hydrate proactively
Encourage regular drinking before and during outdoor activity. Do not rely only on thirst. For most ordinary play and shorter activity, water is appropriate. Longer, very intense, or prolonged activity with substantial sweating may require additional carbohydrates and electrolytes, but needs vary by age, duration, climate, and medical history. Avoid excessive fluid intake as well. For organized sports, follow individualized guidance from the child’s clinician or athletic staff when needed.
To learn more, read this article: Signs of Dehydration In Kids & Infants, Plus Dr. Green Mom’s Homemade Electrolyte Drink Recipe
2. Choose the coolest part of the day
Do not rely only on a fixed rule such as avoiding 10 am to 4 pm. The hottest period varies by location and weather pattern and may extend into late afternoon or evening. Check local heat alerts, humidity, heat index, and when relevant for sports wet-bulb globe temperature.
3. Use air conditioning during dangerous heat
Shade and fans can help in some conditions, but air conditioning is the most reliable protection during extreme heat.
4. Dress for the weather
Choose lightweight, loose-fitting, breathable clothing. Remove unnecessary layers and sports equipment during breaks.
5. Allow time to adapt
Gradually increase the duration and intensity of outdoor activity over 10 to 14 days when a child begins exercising in hot weather.
6. Pay attention to illness and individual risk
Children may be more vulnerable when they have a fever or recent illness, vomiting or diarrhea, poor sleep, a previous heat illness, low physical conditioning, certain chronic medical conditions, medicines that affect sweating or hydration, or heavy sports equipment or clothing. A child who is sick should not be pushed through strenuous exercise in the heat.
7. Teach children to speak up
Teach older children and teenagers to stop and tell an adult if they develop headache, dizziness, nausea, unusual weakness, chills, confusion, or a feeling that something is wrong.
Summary
Heat stroke is a medical emergency involving severe heat stress and abnormal brain function. Warning signs include confusion, unusual behavior, difficulty speaking, loss of coordination, seizure, collapse, extreme drowsiness, and unresponsiveness. A temperature around or above 40°C (104°F) is common, but parents should never wait for a particular thermometer reading before acting.
Call 911 immediately and begin rapid cooling. Move the child out of the heat, remove excess clothing and equipment, wet and fan the skin, and use cold-water immersion for an older child or adolescent with suspected exertional heat stroke when it can be performed safely and the airway can be continuously protected (3).
Do not give fever-reducing medicine. Do not give oral fluids to a child who is confused, extremely drowsy, vomiting repeatedly, seizing, unconscious, or unable to swallow normally.
Infants and toddlers need especially close protection because they cannot move, hydrate, undress, or explain their symptoms independently. Teen athletes require gradual heat acclimatization, appropriate rest and hydration, environmental monitoring, and a culture that allows them to stop when they feel unwell (5).
Never leave a child in a parked vehicle, even briefly. Most pediatric heat illness is preventable through planning, supervision, gradual acclimatization, hydration, access to cooling, and early recognition of warning signs.
References
- Notley SR, Akerman AP, Meade RD, McGarr GW, Kenny GP. Exercise thermoregulation in prepubertal children: a brief methodological review. Med Sci Sports Exerc. 2020;52(11):2412-2422. doi: 10.1249/MSS.0000000000002391. PMID: 32366798.
- Mangus CW, Canares TL. Heat-related illness in children in an era of extreme temperatures. Pediatr Rev. 2019;40(3):97-107. doi: 10.1542/pir.2017-0322. PMID: 30824495.
- Douma MJ, Aves T, Allan KS, et al. First aid cooling techniques for heat stroke and exertional hyperthermia: a systematic review and meta-analysis. Resuscitation. 2020;148:173-190. doi: 10.1016/j.resuscitation.2020.01.007. PMID: 31981710.
- Bin Maideen MF, Jay O, Bongers CCWG, Nanan R, Smallcombe JW. Optimal low-cost cooling strategies for infant strollers during hot weather. Ergonomics. 2023;66(12):1935-1949. doi: 10.1080/00140139.2023.2172212. PMID: 36688597.
- Bytomski JR, Squire DL. Heat illness in children. Curr Sports Med Rep. 2003;2(6):320-324. doi: 10.1249/00149619-200312000-00004. PMID: 14583161.
- National Athletic Trainers’ Association. Exertional Heat Illnesses Position Statement and related emergency guidance.
- National Highway Traffic Safety Administration. Child Heatstroke Prevention: Prevent Hot Car Deaths.
