Babies, toddlers, and toddlers need outdoor activities to develop strong bodies and minds, but they also require extra care in hot weather.

In the summer months, those twin imperatives can make parents anxious. How long should children be away? How do I know they are okay? What should I avoid?

Human-caused climate change is making heat waves longer, stronger and more widespread. Much of the United States sweltered under a dome of heat last week.

That change makes questions about how to keep babies safe more pressing, said Dr. Katherine Williamson, a pediatrician at Rady Children’s Health in Orange, California.

“We talk about drowning and suffocation with young children, and now we’re starting to add heat to it,” he said. “It’s become more common as a possible injury.”

Here’s why children are more vulnerable to heat-related illnesses, and some do’s and don’ts to keep them safe:

Children sweat less than adults and have a higher metabolism which makes them warm up faster. In extreme heat conditions, its higher surface-to-mass ratio increases heat absorption.

Children also tend to spend more time outdoors.

On hot days, parents should watch for signs of heat illness. Lack of tears or regularly wet diapers could indicate that your baby is dehydrated. Parents should feed babies smaller amounts and more frequently to make sure they are getting enough fluid.

Although they are not necessarily signs of illness, fatigue and red skin probably mean that your child needs a break to cool down. Williamson said increased irritability could also indicate that your child is too hot.

Avoid going out during the hottest hours of the day, dress children in loose, light-colored clothing, apply sunscreen, and make sure they drink enough fluids. Water-rich fruits, such as watermelon and strawberries, make great snacks in hot weather.

“If you’re hot, your baby is bound to be hot,” said Dr. Debra Langlois, a pediatrician at the University of Michigan CS Mott Health Children’s Hospital.

Langlois said parents and other caregivers should limit the amount of time babies and toddlers spend outside in hot weather, but he doesn’t recommend staying strictly inside at any time.

That advice seems contradictory. After all, doesn’t it make sense to protect children from the sun?

But blankets and other coverings, even the thinnest ones, prevent air from circulating and trap heat that can raise the temperature in the stroller. Instead, use a canopy for shade.

Williamson also advises parents to check for metal parts that can get hot and burn children.

Even in the shade and with the windows open, the temperature of the car can increase dramatically in a short time. In 2025, 31 children died from vehicle heatstroke, according to the National Highway Traffic Safety Administration.

The agency recommends caregivers leave a purse or other personal item in the back seat, write a note or place a stuffed animal in the passenger seat to make sure they don’t forget a child inside.

If you return to a parked car with your baby on a hot day, make sure the metal parts of the seat are not too hot either. For added comfort, use a sunshade to keep the interior cooler and turn on the air conditioning in advance.

To cool a hot car, experts recommend opening the windows for 10 to 20 seconds while the air conditioning is on.