By Shaun Boyd

DENVER (CBS4)– Since 1998, more than 700 children in the U.S. have died after being left in a hot car.

The first seven months of this year have been the worst in terms of heat-related child car deaths since 2010.

(credit: CBS)

To prevent these deaths, the state legislature passed a new law that protects people who save children or pets in hot cars.

That law takes effect next week and the lawmakers who passed it got a taste of what it was like to sit sealed up in the heat.

Rep. Lori Saine, (R) Firestone (credit: CBS)

Rep. Lori Saine, a Republican representing Firestone and Rep. Joann Ginal, a Democrat representing Fort Collins took what’s become known nationwide as “the hot car challenge.”

(credit: CBS)

With temperatures approaching 90 degrees, they sat in a car, taping a public service announcement about the law. Their goal was to last ten minutes. They made it just over 13 minutes as the temperature jumped from 84 degrees to 104 degrees in the car.

Rep. Lori Saine, (R) Firestone and Rep. Joann Ginal, (D) Fort Collins (credit: CBS)

“We’re trying to raise awareness of how quickly heat climbs in vehicles to show people how uncomfortable it is even within five minutes, being in the shade, windows cracked,” says Saine, “We really want to emphasize the fact that infants and dogs don’t regulate heat, don’t regulate temperature like adults do.”

(credit: CBS)

While adults can get out of a car, she adds, for children or pets it’s a death trap.

The new law gives immunity to Good Samaritans who break the windows of hot cars to rescue a child or pet, if they look for the owner first and call police.

Rep. Lori Saine, (R) Firestone and Rep. Joann Ginal, (D) Fort Collins (credit: CBS)

“You may not even think about this and how hot your car can get in just 10 minutes to a point somebody could die,” Ginal says, “and that’s what this bill is all about, saving lives.”

Shaun Boyd is CBS4’s political specialist. She’s a veteran reporter with more than 25 years of experience. Follow her on Twitter @cbs4shaun.