My only addition, be super careful with the heat packs from the store. They get WAY too hot, easily 165 degrees F. They also release some sort of gas that causes neurological issues in snakes (looks like a really bad spider wobble), and it could kill them. If you use them, don't put the snakes and heat packs in an enclosed area.
I keep some long lasting shipping heat packs just in case something like this happens.