The Thermal Man is a robot that is nearly indestructible. Even Thor had a tough time trying to break him, but ultimately he prevailed. Just as he won in the comic using his lightning, so shall Thor win again. The Thermal Man ultimately doesn’t have the durability to keep on taking hits as well as Thor can. It’ll take a lot of damage to put Thor down, more than the Thermal Man can hope to dish out. This isn’t even counting once Thor enters Berserk mode. Thor wins.