TEXAS (KIAH) — The heat in Texas is intense, but inside a car, it can be deadly.

Nearly 40 children a year die from heatstroke, either because they were left or became trapped inside a car. That’s about one child every 10 days killed in a hot car, according to National Highway Traffic Safety Administration

Looking over data from past years, Texas had the highest number of child deaths from 1990 to 2021 with a total of 146 fatalities.

We haven’t even hit the hottest months this summer, but 7 children have already lost their lives in hot cars in 2023, according to Kids and Car Safety.

These medics closed themselves into a parked car to see how the heat affected the body.

“It’s crazy because initially, it wasn’t bad but 3 minutes in you are like, it’s pretty hot,” said Brian Kynaston, Firefighter/Paramedic.

In about 4 minutes, his blood pressure came down a few points and his heart rate went up 10-15 beats in a minute.

“So definitely it’s taken a toll on his body,” said a fellow firefighter who was monitoring Kynaston’s vitals.

After 10 minutes, the firefighter’s temperature rose to 107 degrees. For reference, the body’s internal organs start to shut down at 104 degrees.

Now imagine if a child or pet was left inside the hot car. A child left alone in a car can overheat five times faster than an adult. And so you know, the interior temperature can rise 20 degrees within 10 minutes, even with the window cracked.

Safe Kids USA said whether your child is sleeping or you’re “just going to be a minute,” don’t risk their lives. Heat stroke is 100% avoidable.