St. Louis ? A 7-month-old infant was found dead in the heat of a parked car Thursday near the Washington University School of Medicine, authorities said. Hours later, a 2-year-old toddler was found dead in a vehicle in a suburb of Cincinnati.

Authorities said the 7-month-old’s parents are a doctor and a medical researcher at the university. Their names and the child’s name have not been released.

The child had been in the car for three hours, police Capt. James Gieseke said. It’s believed the mother left the child in the back seat of the father’s car, but that the father thought the mother had taken the child.

A child also was found dead in a sweltering sport utility vehicle in Union Township, about 20 miles southeast of Cincinnati, police said.