A record 54 children died in hot cars in 2018, followed by 53 fatalities in 2019, according to national nonprofit KidsAndCars.org.
Twenty-five children died in hot cars last year, a drop which KidsAndCars.org director Amber Rollins attributed to the pandemic.
"One thing that [the pandemic] didn't bring down, though, is the number of children who got into cars on their own and died. Those numbers pretty much remained the same as the average," Rollins told ABC News.
Rollins said she's "really concerned" about hot car cases this summer as more parents return to the office and their routines. A change in routine often prompts accidental hot car deaths, she explained.
Rollins said she's also worried about parents who return to work with a hybrid schedule -- working at home some days and in the office other days.
"When your routine is shifting all over the place ... that's one of the most serious risk factors," she 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 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 back seat.
--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 spot a child or pet alone inside a car, "do something," Rollins said. "If they are in distress, you need to get them out immediately and begin to cool them."