Cania

From Fiendish Codex II: Tyrants of the Nine Hells (3.5e):

The frigid layer of Stygia seems a balmy paradise compared to the icy wasteland known as Cania. Mile-thick glaciers grind across a forbidding landscape, only to crash into cyclopean mountains. Screaming snowstorms pelt the white expanse of wilderness. Deep crevasses, often hidden by thin layers of snow, wait to devour the unwary traveler. Dotted across the land like so many signposts are the half-buried, icy corpses of foolish intruders who thought they could survive Cania's arctic rigors.

From Manual of the Planes (3e):

The eighth layer of The Nine Hells is another realm of cold, but Cania's cold is so bitterly penetrating that it is like a living thing. Glaciers moving as fast as a running man grind and crash against each other, sending avalanches of snow down upon any creature unfortunate enough to be caught between the battling ice titans.

The frigid cold penetrates even the warmest natural clothing. Characters take 3d10 points of cold damage every round they are in an unsheltered area in Cania. Moving glaciers often reveal thousand-year-old corpses, past victims of the merciless chill.