Sens. Richard Blumenthal, D-Conn., and Al Franken, D-Minn., introduced legislation on Monday aimed at saving children left in hot cars from death.

"A simple sensor could save the lives of dozens of children killed tragically in overheated cars each year, and my bill would ensure such technology is available in every car sold in the United States. It can take mere minutes on a hot day for a car to turn into a deathtrap for a small child. This basic technology, combined with public awareness and vigilance, can help prevent these catastrophes and save lives," Blumenthal said.

His bill is the Helping Overcome Trauma for Children Alone in Rear Seat Act, or the HOT CARS act. If it became law, cars would be required to have built-in sensors that alert drivers when children are in the backseat and the car is off. The bill was announced on National Heatstroke Prevention Day.

"Each summer, we hear heart-wrenching stories about children whose lives end far too early because they were accidentally trapped in the back seat of a hot car. We can do something to prevent these terrible tragedies, and that's why I've helped introduce commonsense legislation that would make sure there are measures in place to alert you if your child is left in the back seat. I want to see this life-saving technology become the standard in our cars," Franken said.

Last week in Phoenix, A.Z., a 1-year-old and a 7-month-old died of heatstroke after they were left in hot cars.

"A total of 30 children have already died this year and we expect the number of deaths to rise as temperatures climb over the next few months. These deaths are agonizing, they are completely avoidable and there is technology that should be in every car to save lives," said Jackie Gillan, president of Advocates for Highway and Auto Safety.

Reps. Tim Ryan, D-Ohio, Peter King, R-N.Y., and Jan Schakowsky, D-Ill., introduced a companion bill in the House on June 7.