Aura of Frost

An icy chill surrounds you, radiating cold in a 10-foot radius. Creatures of your choice within the aura take cold damage at the start of their turn. Affected creatures must make a Constitution saving throw (DC = 8 + your spellcasting ability modifier + your proficiency bonus), taking 2d6 cold damage on a failed save, or half as much on a successful one. If they fail the saving throw, their speed is reduced by 10 feet until the start of their next turn.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the cold damage increases by 1d6 for each slot level above 3rd.