MEDFORD, Ore. - Authorities say a 6-year-old boy in Medford was flown to a hospital after his parents discovered him in the trunk of a car, suffering from a heat-related illness.

The boy was found alive Tuesday evening. He was taken to a nearby hospital and soon transferred to Doernbecher Children's Hospital in Portland.

He remains in critical condition.

Police said each of the boy's parents thought he was with the other parent. He was missing for about 40 minutes when the parents realized he wasn't with either of them. When they searched for him, they found a phone he was playing with in the back seat of the car, which prompted them to look in the trunk.

Neighbors called the family "very loving."

Detectives are investigating the incident. At this point they don't expect to file any charges.

Temperatures in Medford reached 89 degrees on Tuesday. Cars can quickly heat to many degrees over air temperature on hot days.