The guard spotted the boy at 3:38 p.m. in a vehicle parked at the Sears store at 800 S. State St. The guard could see he was perspiring, even though the weather was overcast and the car window was left slightly open, said Lt. Gary Young with the Salt Lake Police Department.

The guard broke the car window and pulled out the boy, who was found to be suffering from heat exposure. Young said the boy was left in the car about an hour.

"I guess the parents forgot to read the rule book, " Young said. "One of the rules: Don't leave your kids in the car. I guess they forgot that."

The boy was taken to Primary Children's Medical Center as a precaution. It was not immediately known Monday if he had been released.

Young said the district attorney will investigate the incident to determine if charges will be filed against the child's parents. Names of the people involved in the incident have not been released.

In April, a Kearns woman left her 18-month-old son Myles in her car while she was unloading groceries, then forgot about him. When she came back three hours later, he was unconscious and was later died of heat-related causes.