I babysit 3 grandchildren the oldest is 4 ,and there is no way I can walk into a store to pick up a pizza etc. with the 3 of them. I have parked right in front of the window and walked in. I lock the doors, the children are in their car seats and the windows only cracked. I know something can happen in a second, but how can you always have all children at your side when you go pay for gas etc. to be away for 1 minute. I am very conscious of every second I am away from their side and they never leave my line of vision or if someone is too close to the car, I run back to it.
However in our city we have had 2 very educated women (1 a professor and 1 an assistant principal) who left their children in the hot car all day resulting in the children dying and nothing happens to them. I think it is time for people to be responsible for their actions and pay attention to what they are doing. I can't imagine not looking in your back seat to see if anything or anyone is there before you get out of a car. If people complain about this, I think people are afraid they will come up with riduculous laws, like stopping by a trash can to throw trash out and not taking the children with you, that you will get arrested.