I would never leave my dog in the truck on a hot day. But, I see no problem with running into the store for 5 minutes, while my dog waits, with the windows rolled down.
Theres a growing movement in my town of wannabe heroes, looking to get some internet cred.
For example this self-proclaimed biker lady that drives a spider:
"Just a small warning to all Wasaga locals and visitors to the area. IF you have a dog, cat, or child locked in your car in this scorching heat and you come to find out that your windows have been smashed and the animal or child is missing, you can bet your bottom dollar I saw it first and it was me. Oh ya, I'm the one with a half a dozen cops with me when you come out. Thank in advance for trying to hit me, and you getting arrested. You're welcome."