Hot car deaths are on the rise as the temperatures heat up outside.

According to, 19 children have died in hot cars so far in 2017. One of those deaths happened in Chattanooga last weekend.

Dr. Gary Hurt, assistant medical director at the University of Tennessee Medical Center, said it only takes a matter of minutes for a car to heat up and a child to suffer the effects of a heat stroke or worse.

"The temperature inside a vehicle can quickly reach anywhere between 120 to 140 degrees Fahrenheit in as little as 20 minutes," Hurt said.

10News Meteorologist Mike Witcher put this to the test in East Tennessee Tuesday afternoon by placing a heat sensor inside a car for about an hour.

Witcher reported, "It started off at 74 degrees. It rose to about 150 at one point."

WATCH: How hot does it get inside a locked car on a warm day?

Hurt said temperatures that hot are enough to cause a child or pet to die.

"Even in a short period of time, vehicles can get extremely hot," Hurt said, "even if you sort of crack the window as some people do."

Hurt said infants can only regulate temperature by evaporative cooling, but car seats that children are often placed into can decrease the ability for the child to sweat and cool off. He said a child's body temperature can quickly rise in a car when the windows are closed or slightly cracked, and they can develop a fever, which can cause significant brain damage or death.

"It's almost like putting them in an oven," Hurt added. "The temperature increases. The humidity increases."

Darrell DeBusk, Knoxville Police Department public information officer, said there are "Good Samaritan" laws in place to protect people if they report a child or pet left in a car.

"We obviously would rather them call it in and prevent an injury to a child or to a dog than for them not to and the worst happen," DeBusk said.

He said it is legal for a person to break a car window if a child or pet is left inside a car, but the person must follow the proper procedure.

"Call 911. Check to make sure it's not unlocked before trying to break a window," DeBusk said, "and then obviously, do what you have to do to get into that vehicle."

Lawmakers introduced the Hot Cars Act of 2017 in the U.S. House of Representatives earlier this summer. It would require all vehicles to have alarms reminding drivers to check their back seats.

Even if it passes, doctors and law enforcement encourage other tips for parents to remember children in the car, such as leaving a shoe or a cell phone in the back seat.