A 4-year-old boy died after he was left for 90 minutes in a stifling hot vehicle while outside temperatures in Las Vegas reached 100 degrees.

Officer Laura Meltzer said Friday that Las Vegas police were called just before 6:30 p.m. Thursday, after the boy was found in the vehicle at a home east of downtown.

He was pronounced dead at Sunrise Hospital & Medical Center.

No arrests have been made.

Lt. Tom Melton told the Las Vegas Sun the child's grandfather said he had the boy with him while running errands, and they returned home about 5 p.m.

Kids and Cars, a nonprofit that tracks child deaths and injuries in and around automobiles, says it was the 16th such case of its kind in the nation this year.