A study funded by General Motors of Canada found that within 20 minutes the air temperature in a previously air-conditioned small car exposed to the sun on a 35ºC day (95º F) exceeded 50ºC (122º F). Within 40 minutes the temperature soared to 65.5 ºC (150º F).
Leaving a window slightly open, or "cracked," did little to prevent the inside the vehicle from becoming dangerously hot.
An average of 37 deaths take place per year in the United States (no statistics are available for Canadian cases). The majority were age three or younger.
It may come as a surprise that more than half of the children left in hot cars were trapped there unintentionally, forgotten in a moment of absent-mindedness, or trapped after playing unsupervised in an unlocked vehicle.
Look twice before locking. Always keep cars locked while in garages or driveways to prevent children and animals from inadvertently becoming trapped. The Canada Safety Council suggests making a habit of placing your cell phone, purse or wallet in the back seat -- a strategy that requires you to turn around and check the back seat whenever you leave the vehicle. If you come across a child or animal in distress that has been left in a hot vehicle, call 9-1-1. Never leave a child or pet alone in a vehicle, even for a few minutes.