WARWICK — The child found dead Sunday in his family’s parked car died of heart failure due to overheating, Maj. Joseph H. Tavares of the Warwick police said Monday.

Tavares identified the child as James A. Lymburner, 3, of 42 Suburban Parkway. He said the cause of death was determined after an autopsy by the state medical examiner.

The boy was not in a car seat when he was found in the Jaguar parked in front of the family’s house, Tavares said, and the police believe he had climbed into the car on his own. Tavares called the incident “a tragic, tragic accident.”

The Oakland Beach family had called the police to report the boy missing. As the police arrived, a family member noticed the boy in the back seat, according to the police, who said he apparently climbed into the car on his own.

Officers performed CPR until an ambulance arrived and took the child to Hasbro Children’s Hospital, where he was pronounced dead.