Last year saw a record number of hot car deaths: 51. So far this year, 32 kids across the country have died, including a little boy in South Florida a couple of weeks ago.Now, parents of victims are taking action. WESH 2 News spoke to one of those parents. A mother said she made one mistake -- one change in her daily routine. She put her infant son in the back seat, taking him to daycare. The result? He was left behind. She and other parents want car makers to have active systems to detect kids in rear seats, and warn drivers. It took virtually no time -- just 25 minutes -- for the temperature in that car to rise from 70 to 120 degrees -- heat that can kill. No one knows that better than Gannon Werking's mother, Stephanie Salvilla. "My whole world had stopped. I didn't think it was ever going to be the same. I mean, I knew all of my hopes for my son were gone," she said. Salvilla had a morning drop-off routine to ensure she never left her kids in the back seat -- a routine that suddenly changed in 2009, when she said she dropped off her older daughter, but drove to work and discovered her son Gannon at the end of a very hot July day. "I had done everything I could, I thought I could, to make sure my children were safe," Salvilla said. General Motors, Subaru, Nissan, Hyundai and Kia are all adding systems that when a vehicle is turned off, chimes will go off and messages will appear to warn people to check the back seat. But the families of 50 children who have died in hot cars wrote a letter to GM Chair Mary Barra, saying, "the current door GM system will not solve the problem, and children will continue to die." It also points out GM's promise in a 2001 news release to install by the 2004 calendar year, a "sensor that will focus primarily in the rear seating area, where children are most likely to be, that would trigger a unique horn alarm" if the back seats were not checked. The head of , Amber Rollins, told WESH 2 News that 600 children have died since 2004. "This technology has been in existence for over 20 years. There's no excuse why we continue to allow children to die in hot cars," Rollins said. GM responded to the letter this way: "Systems that accurately and reliably detect children in vehicles have not been widely deployed across the industry due to continued challenges with … accuracy… given the broad number of vehicle/seating configurations." All manufacturers will be forced to ramp up their safety if the Hot Cars Act passes. It would demand that all passenger vehicles have systems to, "detect the presence of an occupant in a rear designated seating position ..." It's technology Salvilla believes will prevent another tragedy like her son's death. Since 1990, nearly 1,000 children have died from being in hot cars, and yet, our WESH 2 News review of owners manuals for most vehicles on the road shows they have a lot to say about child safety restraints, but say little or nothing about the dangers of hot cars.