Frostbrand

Frostbrand weapons are designed to fight creatures with an affinity for fire.

In second edition they deal extra damage to creatures that wield the power of fire or live in fiery environments. They have a fifty/fifty chance of extinguishing even magical flames within ten feet of the thrust blade and halve the damage that fire does to its wielder and emits light in temperatures below 0°F. In addition, it provided all of the protections of a ring of fire resistance.

In third edition they dealt extra cold damage to anything they struck, protected its wielder from fire damage but only extinguished nonmagical flames however it still shed light when it was below 0°F. They could attempt to dispel magical fires though.

http://fc09.deviantart.net/fs31/i/2008/200/f/d/Frost_edge_Katana_by_Escrimator.jpg