Plenty of Earth animals with fur that live in tropical or arboreal areas. Take a gorilla to Antarctica and see how he'd fare.He's the only one with fur. And he could put on some pants and a sweater. And we're tree dwellers. And why does he have fur if his home planet is hot?
(...we're tree dwellers?)
Anyway, the movie established it was too cold at night for any living thing outside the protection of caves, artificial shelters, or specially-equipped vehicles (which weren't ready yet).
So while we're on ESB...they left behind Luke's X-Wing at Imperial-occupied Cloud City, but he has it back in ROTJ.