Belt of Antipode

Belt of Antipode gives immunity to cold, but doubles the damage received from fire-based attacks. It can be worn by any class.

The belt is found in Gorion's corpse in Baldur's Gate: Enhanced Edition.

In-game description
"Trimmed in the fur of a polar bear, this sturdy belt is tooled with images of blue moons and white ice floes. The wearer is immune to all cold-based effects but suffers double any fire damage."