Saturday marks the first day of summer -- an important reminder that as the temperature climbs, so does the danger for children left in hot vehicles.
Fifty-three children died in hot cars in 2019, which followed a record high of 54 hot car deaths the year before, according to national nonprofit KidsAndCars.org.
Five children have died in hot cars so far in 2020, according to KidsAndCars.org.
"We believe that the pandemic has had a major effect on reducing the number of fatalities we've seen this year," KidsAndCars.org director Amber Rollins told ABC News last week.
"We are concerned that as people begin to return to work and routines are disrupted again, that there will be an increased risk for children being unknowingly left in hot cars due to the changes of routine," Rollins said.
Editor's note: This article was initially published in 2019.
The science behind hot cars
Children's bodies heat up much faster than adults do, according to the nonprofit National Safety Council.
Children's internal organs begin to shut down once their core body temperature reaches 104 degrees -- and it takes very little time for a car to get too hot for children, according to a report published by the council in 2018.
On an 86-degree day, for example, it would take only about 10 minutes for the inside of a car to reach a dangerous 105 degrees, researchers said.
What you can do
Rollins from KidsAndCars.org offers these tips for drivers:
--Always keep cars locked even if you don't have children.
--Always keep keys out of children's reach.
--Place an item you can't start the day without in the backseat.
--If a child goes missing, check the inside and trunk of all cars in the area immediately.
--Teach children to honk the horn if they get stuck.
"If you see a child or animal alone in a car, do something," Rollins said. "If they are in distress, you need to get them out immediately and begin to cool them."
KidsAndCars.org officials and dozens of other consumer, health, safety and animal protection organizations are pushing for federal legislation that would require available and affordable car technology that they say would help prevent these tragic deaths.