CHARLOTTE, N.C. – Two young kids were left alone in a car for hours on one of the hottest days of the year.

Now, their mother’s arrest is highlighting the danger of kids in hot cars.

The police report shows the girls, ages four and five, were locked inside the car for several hours on the 1400 block of Samuel Street. Police say 25 year-old Milicia Middleton left the girls in a locked car with no food or water.

“Leaving kids in hot cars even for a few minutes can potentially be life threatening,” says Lester Oliva, community engagement coordinator for MEDIC.

Police say the girls who were sent to the hospital were in the vehicle from about 7 p.m. to 9:30 p.m. on Sunday. NBC Charlotte’s Chief Meteorologist Brad Panovich says temperatures at that time were between 75 and 80 degrees outside.

“If it wasn’t for those storms, the outside temperatures would have been around 90, 95 degrees, but even with a temperature of 78, 79 degrees, after about 30 to 60 minutes the temperature in the car still gets to 120 degrees,” says Panovich.

Experts say when it’s 80 degrees outside, the inside of a car gets to 109 degrees after just 20 minutes. After an hour, the inside of a car gets to 123 degrees.

Last year, 39 children died in the U.S. after being left in a hot car, including three in North Carolina.

MEDIC says to call 911 immediately if you see children left in a car.

“Don’t think someone else already called 911, if you don’t see first responders there, call 911,” says Oliva.

In the latest case, the two girls had minor injuries.

Their mother is now facing a charge of misdemeanor child abuse. The case remains under investigation.