If you have any doubts (I'm sure you don't) about how hot and dangerous a car can be for your dog on a warm day, check out the experiment by the KING 5 Morning News folks. Producer Elizabeth Berman put a thermometer inside her car in the middle of the day and let the video roll. Watch the video
The temperature rose from 80 degrees to more than 115 degrees within an hour. Elizabeth says when she left work at 4 p.m. the temperature in her car was up to 127 degrees!
It's never good to leave pets in the car in warm weather. the temperature can rise to a dangerous level even if the car is parked in the shade.
Pets can quickly succumb to heat exhaustion, heat stroke, brain damage or death.
If you happen to see a pet in a car alone, alert the management of the store where the car is parked. If the owner doesn't return promptly, call local animal control or the police department.
The Humane Society of the U.S. has an informational poster you can print out.