Officers were called around 1:30 a.m. Saturday to the Chickie's and Pete's restaurant, located in in the Cardiff section of the township.
When they arrived, they found bystanders had already removed Brandon Morgan's 3-year-old from the car.
Investigators say the toddler had been left in the vehicle, which was not running, for three hours.
Despite the 85 degree heat, the boy was okay and was released to his mother.
Morgan is now facing a number of charges, including child endangerment.