Why does Heat enter car when heater switch is off?

If you find your self living anywhere where it gets pretty hot in the summer, you'll want to know what locals know about summer car safety. Having the right items--and never having the wrong items--in your vehicle will make driving in the heat a much safer and enjoyable experience.

If you ever park outside during the summer months, your car will heat up quickly. Heat coming in through the Windows is absorbed by the interior, and the glass acts as an insulator. The temperature in your car get up to 200 degrees, depending on the temperature outside, the kind of vehicle you have, and how long it has been in the sun.

Now we know how the sun works. Some cars have flow through ventilation, there is air movement all the time. You can move the temperature to cold and just the outside air will go through. The door that shuts the heater off may not be sealing completely. Either the seal is bad or the control valve isn't closing it completely. Some cars have less insulation in the floor and it may be radiant heat.