I was reading up on Norse Mythology, and I was inspired to paint Niflheim, which was the Norse version of Hell. It's described as being cold, dark, and misty. This undeworld is ruled by Hel, the merciless daughter of Loki, who appears as a beautiful woman from the waste up, but has only skeleton legs. If you were a viking, and you had the misfortune of not dying battle, but bed, you might end up here.
The cold blue fires are lit by the denizens of this realm, and frozen into the cliff is the corpse of a frost giant who displeased the cruel goddess.