There was mention in the initial idea of two different Cults, one worshiping an ancient ice dragon, and the other worshiping an ancient gold/red dragon. The one who worships the ancient ice dragon is blamed for the cold that has folded over the world, while the other is blamed for the infernal heat that preceded the cold. I don't know if this idea was even kept through the various changes.
The fire and ice cults. With the cold cult working to keep the cold going and the fire cult trying to bring the world back into balance.
The two cults remain, because I want to keep them in some capacity, but I just haven't exactly figured out how yet. the Fire Cult is, oddly, easier to keep since they can be renegades from the Covenant. The Cold Cult, though... that's more tricky.