CBS Local — Eleven children died from heatstroke in overheated cars in July, making it the deadliest month for child hot-car deaths in almost a decade.

July is normally the deadliest month for children in hot cars, and the highest death toll was 16 in 1999, meteorologist Jan Null of Golden Gate Weather Services told USA Today.

The July death toll last reached 11 in 2008.

About 37 children die while trapped in overheated vehicles every year in the U.S., and at least 729 have died in hot-car incidents since 1998, Null said. In 2017, 29 children have already died.

“The warmer months are the biggest variable, but in summer months people’s routines are changed, so that could be a contributor,” Null said.

But these incidents do not occur exclusively during the summer months. Overheated vehicle deaths have even happened in colder months like December and January.

“It does not have to be an extremely hot day for these incidents to happen,” Null said.

Cars can become overheated when direct sunlight heats a vehicle’s interior. Temperatures in vehicles can climb as high as 120 or 130 degrees when the outside temperature is only in the 80s.

The human body’s natural cooling methods, including sweating, start shutting down once a person’s core body temperature reaches 104 degrees. Death occurs when that temperature reaches 107 degrees.

The death toll of children perishing inside hot vehicles has soared since the mid-1990s, Null said.

The rise can be at least partially attributed to the requirement for children to sit in back seats after juvenile deaths from air bags peaked, as children are more easily forgotten in the back seat than they are in the passenger seat.

The last two children who died in hot cars are 7-month-old Zane Endress and 1-year-old Josiah Riggins, both of Arizona, who died within a day of each other last week.

[H/T: USA Today]