My puppy just threw up clear vomit with white foamy stuff. Its really hot out & I'm worried.. help!!

Is your puppy acting strange at all? More sleepy than usual, more thirsty, is he/she eating normally?
Also is the vomit yellow or clear like water?

If you're really concerned you should contact the vet, it might be nothing, but you never know and it never hurts to have a professional opinion.

At the very least, call your vet and get his opinion. Personally, I would take him in to the vet. It may be that it's just overheated but it could be something more serious.

Good luck.

He may have drunk too much water due to the heat. My dog used to do that. IF it continues or if other things change I would call your vet for advise.