Study: Car Interiors Reach Dangerous Temps All Year
July 24, 2014 -- After a string of high-profile cases of kids being left in hot cars this year, a new study shows just how quickly heat can become a danger, even in cooler months of the year.
Researchers in Texas measured in the temperatures inside a car on a single day each month in 2012, checking temps every 5 minutes from 8 a.m. to 4 p.m. They hung the thermometer in the back seat, out of the sun, about where a child’s head would be if they were sitting in a car seat.
“We wanted to simulate what might happen on an average work day,” says Sarah Duzinski. She’s a research scientist at Dell Children’s Medical Center in Austin.
They took care to pick days that were sunny, with little cloud cover, but they also tried to stay away from extreme weather. They only sampled on days when the temperature was going to be within about 20 degrees of the historical average.
“What we found, in Austin, at any rate, is that children face the threat of hot car death in every month of the year,” Duzinski says.
In all 12 months, temperatures rose to at least 90 degrees in the car. Ninety degrees is the point where the National Weather Service says people should use "extreme caution," because the risk of heat illness is higher. In all but 2 months -- December and January -- temps inside the car shot up to National Weather Service “danger” levels of greater than 105 degrees.
In June, the hottest day they measured, temps inside the car topped 90 degrees by 8:35 a.m. and hit 105 by 9:25 a.m. In some cooler months, including February, April, October, and November, temps were over 90 degrees in the car before noon.
If a child was in the car, “it wouldn’t take long for that child to [die],” Duzinski says.
How soon temperatures become a danger to kids varies. How well children tolerate heat depends on how acclimated to the heat they are, how much water they’ve had to drink, and genetics, among other things, she says.
Hot cars also become more dangerous as children breathe and sweat, which raises the humidity level. More humidity makes it even tougher for little bodies to stay cool. Because of their smaller size, children can overheat three to five times faster than adults.
Beware of Cooler Outside Temps
Cooler fall and spring temperatures can be dangerous, too. A previous study in the journal Pediatrics found that even when the temperature outside is a mild 72 degrees, the temperature inside a car can rise as much as 40 degrees within an hour. This study showed that even when outside temperatures were as low as 68 degrees, the inside of a car can reach temps greater than 105.