Jul. 24, 2010 07:05 AM   The Arizona Republic

The Phoenix Fire Department urges people to use extreme caution during the Valley summer's extreme heat.

When temperatures outside reach 100 degrees, the temperature inside a car can reach 138 degrees in five minutes and 150 in 15, even with a window partially open. Having the windows down even 1 inch causes only a slight temperature drop.

In these conditions, children and pets can die in a matter of minutes. Infants and small children are particularly vulnerable; the younger the child, the faster the onset of heat stroke and dehydration.

Dark cars reach slightly higher temperatures than light cars, but larger cars heat up just as fast as small ones. And the greater the amount of glass in the car (hatchbacks, for example) the faster the rise in temperature.

Read more: http://www.azcentral.com/news/articles/2010/07/23/20100723phoenix-fire-department-cars-summer-tips.html#ixzz0v0E3Jf4l