Doom of Consuming Fire

You are wreathed in cold, purple fire that damages creatures near you. You take 1d6 cold damage each round for the duration of the spell. Creatures within 5 feet of you when you cast the spell and at the start of each of your turns while the spell is in effect take 1d8 cold damage.

At Higher Levels. When you cast this spell using a 3rd level spell slot, the purple fire extends 10 feet from you, you take 1d8 cold damage, and other creatures take 1d10 cold damage. When you cast this spell using a 4th-level slot, the fire extends 15 feet from you, you take1d10 cold damage, and other creatures take 1d12 cold damage. When you cast this spell using a slot of 5th level or higher, the fire extends to 20 feet, you take 1d12 cold damage, and other creatures take 1d20 cold damage.