As a country, we have been warned to never let a child wait in the car, as if merely waiting briefly in a parked car leads to death.
Fortunately, a 2010 study published in Forensic Science, Medicine, and Pathology looked at the actual circumstances surrounding the deaths of kids in non-moving cars. (Recall that the most dangerous place for a child in America is a MOVING car. In 2007, 36 children died of heatstroke in cars, while 905 died in crashes. Maybe we should criminalize driving?)