Chilling Cloud

You create a 20-foot-radius sphere of bitterly cold fog centered on a point within range. The sphere spreads around corners, and its area is heavily obscured, reducing visibility to 5 feet. The sphere lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. A creature starting or ending its turn in the area of effect must make a Constitution saving throw. On a failed save, the creature takes 3d4 cold damage and half that amount on success.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the radius of the fog increases by 20 feet and the cold damage increases by 1d4 for each slot level above 3rd.