LANCASTER, S.C. - Authorities say a 3-year-old boy is in critical condition suffering from heat stroke after he accidentally locked himself inside a car in Lancaster while playing outside.

Lancaster County deputies said the boy's mother discovered her son left the house without her knowing and found him trapped inside the car with the family dog around 1:15 p.m. Wednesday.

Investigators said the dog died, while the boy was taken to the hospital.

Deputies and workers from the Department of Social Services are investigating the incident. No charges have been filed.

Temperatures in the area were around 90 degrees when the boy locked himself in the car.