As extreme heat slams the U.S., it's important to remember the dangers of leaving children in hot cars.

Eleven children in the U.S. have died from hot cars so far this year, from Pennsylvania to Virginia to Texas, according to national nonprofit

A record 54 children died in hot cars in 2018, followed by 53 fatalities in 2019, according to

It's especially important to be mindful of hot car safety as more parents return to the office and their routines, director Amber Rollins said. A change in routine can often prompt an accidental hot-car death, she explained.

Rollins said she's also worried about parents who return to work with a hybrid schedule (working at home some days and in the office other days.)

"When your routine is shifting all over the place ... that's one of the most serious risk factors," she said.

The science behind hot cars

Children's bodies heat up much faster than adults' do, according to the nonprofit National Safety Council.

Children's internal organs begin to shut down once their core body temperature reaches 104 degrees, and it takes very little time for a car to get too hot for children, according to a report published by the council in 2018.

On an 86-degree day, for example, it would take only about 10 minutes for the inside of a car to reach a dangerous 105 degrees, researchers said.

PHOTO: In this undated stock photo shows a car parked in the sun on a street.
STOCK PHOTO/Getty Images
In this undated stock photo shows a car parked in the sun on a street.

What you can do

Rollins offers these tips for drivers:

-- Always keep cars locked even if you don't have children.

-- Always keep keys out of children's reach.

-- Place an item you can't start the day without in the back seat.

-- If a child goes missing, check the inside and trunk of all cars in the area immediately.

-- Teach children to honk the horn if they get stuck.

-- If you spot a child or pet alone inside a car, "do something," Rollins said. "If they are in distress, you need to get them out immediately and begin to cool them."