Deals on-going cold damage to the target every 2 seconds for 12 seconds. The damage starts small, and grows larger as the spell continues. Each phase lasts 4 seconds.

First phase: 2d4 damage +4 per 2 caster levels (max +40 at caster level 20).
Second phase: 4d4 damage +6 per 2 caster levels (max +60 at caster level 20).
Third Phase: 6d4 damage +8 per 2 caster levels (max +80 at caster level 20).