It's Frost Damage

It's Frost Damage is a dungeon & raids achievement earned for allowing three Freezing Vapors to cast Coalesce during the Admiral Ripsnarl encounter in Deadmines on Heroic difficulty.

Strategy
To obtain this achievement you do not have to be alive, as long as one of the party members manages to stay alive until one of the Freezing Vapors casts Coalesce three times. The easiest way to do this is to have all party members stay inside the hut and pretty much kill the rest of the adds, try to heal the members (preferably the one with the most health points) and leave one add alive to cast the spell.