Idaho State Police are investigating the death of a 2-year-old boy who was found in a hot car outside a Rathdrum home.

The toddler had been playing and was discovered in the car late Sunday afternoon by family, who called 911, according to a news release issued by ISP. The temperature was around 92 degrees.

When Rathdrum police arrived at the scene, they attempted lifesaving measures. However, the child was pronounced dead at the scene.

Idaho State Police took over the investigation, which remains ongoing, at the request of Rathdrum police.

Investigators have not yet determined how long the child was inside the car, ISP confirmed Monday.

The Kootenai County Coroner’s Office will determine the cause of the child’s death.

Children are more vulnerable to heatstroke than adults, according to Eastern Idaho Regional Medical Center. Once a child’s internal body temperature reaches 104 degrees, organs begin to fail. At 107 degrees, a child can die.

It doesn’t take long for a child’s body to reach these extreme temperatures inside a hot car, even if the car is parked in the shade or windows are left partially open. The inside temperature of a vehicle can rise almost 20 degrees within the first 10 minutes.

Nearly three in 10 heatstroke deaths in children occur when they gain access to a parked, unlocked vehicle, according to the National Highway Traffic Safety Administration. Children may climb in a car and then be unable to get out.

Parents and caregivers should make sure to lock the vehicle when at home and keep the keys in a secure place that children can’t reach. This prevents kids from getting into a parked vehicle to play and accidentally trapping themselves inside.

The Centers for Disease Control advises caregivers never to leave babies or children in a parked car. When leaving a vehicle, check to make sure everyone gets out, taking care not to miss sleeping children.

Last year, 33 children in the U.S. died of heatstroke in vehicles, including a baby girl left in a hot car in New Plymouth, Idaho.