Health experts say babies, toddlers and young children need outdoor play for healthy growth and development, but parents should take extra precautions to protect them during periods of extreme heat.
As climate change contributes to longer and more intense heatwaves, doctors say heat-related illnesses are becoming a growing concern for children.
"We've always warned parents about risks like drowning and choking, and now heat is becoming another major safety concern," said Dr. Katherine Williamson, a pediatrician at Rady Children's Health in Orange, California.
Why children are more at risk
Experts say young children overheat more quickly than adults because they sweat less and have a faster metabolism. Their bodies also absorb heat more easily due to a higher surface-area-to-body-mass ratio.
Since children often spend more time outdoors, parents should closely watch for signs of heat-related illness.
For infants, fewer wet diapers or a lack of tears when crying may indicate dehydration. Doctors recommend feeding babies smaller amounts more frequently to help keep them hydrated.
Tiredness, flushed skin and unusual irritability are also signs that a child may be getting too hot and needs to cool down.
Ways to keep children safe
Doctors recommend avoiding outdoor activities during the hottest part of the day whenever possible. Children should wear loose-fitting, light-coloured clothing, use sunscreen and drink plenty of fluids.
Water-rich fruits such as watermelon and strawberries can also help keep children hydrated.
"If you feel hot, your baby is almost certainly feeling even hotter," said Dr. Debra Langlois of the University of Michigan Health C.S. Mott Children's Hospital.
She advised limiting the amount of time babies and toddlers spend outside during very hot weather, although she said there is no need to stay indoors all day.
Avoid covering strollers with blankets
Health experts warn against placing blankets or cloth covers over baby strollers to block the sun.
Although it may seem helpful, coverings reduce airflow and trap heat inside the stroller, making it much hotter for the child.
Instead, parents should use the stroller's built-in sunshade or canopy. They should also check metal parts of the stroller, which can become hot enough to burn a child's skin.
Never leave children in a parked vehicle
Doctors also stress that children should never be left alone inside a parked vehicle, even for a short time.
Temperatures inside a car can rise rapidly, even if the windows are partly open or the vehicle is parked in the shade.
According to the US National Highway Traffic Safety Administration, 31 children died from heatstroke in vehicles in 2025.
The agency recommends placing a personal item, such as a handbag, in the back seat or putting a stuffed toy on the front passenger seat as reminders to check the back seat before leaving the vehicle.
When placing a child in a parked car on a hot day, parents should also make sure the car seat and metal buckles are not too hot.
Experts recommend using sunshades to keep the vehicle cooler and running the air conditioner while opening the windows briefly to help remove trapped hot air before putting a child inside.