Walker County Sheriff Steve Wilson said an infant who was pronounced dead after being brought to Hutcheson Medical Center in Fort Oglethorpe had been left in a parked car for five hours.
The child's grandmother was babysitting the child, while the mother was at work, it was stated.
The 13-month-old, Shadoe "Braxton" Pate, was left outside a home in the Fairview community on Tuesday.
Sheriff Wilson said the motor was left running and the heat was on low in the car.
Initial findings were that child died from extended exposure to heat. The temperature in the car is believed to have gone above 100 degrees.
The grandmother is being tested for drugs.
An investigation is being conducted by the Walker County Sheriff's Office, the Georgia Bureau of Investigation and the Walker County Coroner's Office.
An autopsy was being conducted at the GBI Crime Laboratory in Decatur, Ga.