No is the safe answer. But really, for how long? For two minutes while you run into a store to buy your puppy a new toy? Then maybe yes to the AC and the car running while puppy is in crate.
No to the windows open. He's pretty cute, I'd steal him myself. If I saw that poor puppy had an owner dumb enough to leave him alone like that I would feel it my duty to save that poor puppy. I am only partly kidding.
REad this whole thread, please.
I hope you are not comtemplating leaving such a young pup all alone in a crate while you are at work? A rule of thumb for crating time is one hour plus one additional hour per month of age. So that allows you, what? Nearly two hours?
How long are you thinking of leaving him in the crate?