By Jeff Rossen, Josh Davis and Lindsey Bomnin, TODAY

The deaths of an 8-month-old baby boy trapped in a hot SUV in North Carolina and an 11-month-old girl left inside her parents' parked car in South Florida are sad reminders of how quickly hot cars can kill children. Summer hasn't even started yet and already cases are spiking across the country. Nine children have been killed so far this year — a 350 percent increase from this time last year.

In 10 to 15 minutes, a car parked with its engine not running can go from 80 degrees to 130 degrees, a police officer told Rossen Reports.

In Miami, TODAY national investigative correspondent Jeff Rossen showed how hot it can get inside a car, and demonstrated how to safely rescue a child trapped inside one.