Leaving a dog in the car in the Las Vegas heat isn't just illegal in the state of Nevada, it's classified as animal cruelty. One man confronted an owner who'd left his dog unattended and said exactly what we were all thinking.
"You sir, are an asshole."
Yes, he is. And if a cop had found this scene rather than some guy with a cameraphone, that officer would take the dog away, as Nevada State Law points out.