jenaust wrote:I would NEVER take her anywhere with me in the summer when it is easily over 110 degrees. *guess I should have been a little more detailed*I take her places with me in the late fall/winter when it might get up to the mid 70's - low 80's. I had no idea how much of a touchy subject this would be. I now feel like you all think I am a horrible pet owner. I would never do anything to hurt my dog (or any animal for that matter!).
Mid 70s low 80s is still too hot to have an animal left in a car. I'd advise looking at this web page, and paying special attention to the 'How hot do cars get?' ink:
http://www.mydogiscool.com/
They took measurements from a car over a three day period with and without cracked windows, and comparing the interior temps with the exterior temps. Notice that the first readings of the day are within the range you describe.
While you could leave the car idling with the AC on, aside from the previously mentioned legal issues, there have been cases where cars have overheated and shut the engine off or the AC malfunctioned and the animal(s) inside perished.
I actually found a little dog locked in a car when the outside temp was 75, with the car parked in the middle of a mall parking lot with all the windows rolled up. The dog was panting like crazy, and I called mall security on my cell phone. They came out, opened the door, and got the dog out. The whole thing took about 20 minutes, and during that time there was no sign of the owners.
Your dog would be better off left at home.