By Christina Maxouris, CNN

A Maryland woman has been charged after officers responded to a 911 call to find seven children trapped inside a hot car.

The oldest child in the car, a 4-year-old, called police to report they had been left unattended, but said he didn't know where they were.

"Through GPS and other mechanisms, the call-taker was able to pinpoint the location of the vehicle," the Charles County Sheriff's Office said in a statement.

When officers arrived, they found the car turned off and its windows rolled up.

The youngest child in the car was 2 years old.

Charles County Fire/EMS provided treatment to the children on the scene, the sheriff's office said. CNN affiliate WJLA reported they were "scared" and "sweaty." The news station also said police discovered only one car seat inside the car.

The woman who had left the children was the mother of two of them and was babysitting the others, according to the sheriff's office. She arrived at the vehicle about 10 minutes after police and officers determined she had been shopping inside a nearby mall for at least 20 minutes.

She was charged with confinement of children inside a motor vehicle and additional charges are pending, the sheriff's office said.

"As a reminder, it is against the law to leave a child under the age of eight unattended inside a motor vehicle if the caregiver is out of sight of the child unless a reliable person at least 13-year-old remains with the child," the sheriff's office said. "It is also dangerous to leave anyone, including pets, inside a motor vehicle especially as outside temperatures become warmer. The temperature inside a parked car can quickly rise to extremely high and even fatal levels in a short period of time."