Coldbrim Chill: Once per turn, any condition inflicted on a target, also applies 2 turns of Encrusted with Frost.
Upturning the hat and gazing into it, you get this slightly vertiginous feeling, as if you were looking into a cold, abandoned well with no discernible end.
Discussion
Moonrise Towers X: -155 Y: -173: Found in a locked chest in a hidden room behind a bookcase in Balthazar's Chambers.
Sorcerous Sundries: Found on a table by the Lava Elemental.
Act Two:
Found in a locked chest in a hidden room behind a bookcase in Balthazar's Chambers within Moonrise Towers.
Act Three:
Found on a table by the Lava Elemental in Sorcerous Sundries.