Cloud of Frost

You create a 20-foot-radius sphere of fog centered on a point within range. The sphere spreads around corners, and its area is heavily obscured. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it. All creatures who start their turn within the cloud or enter it during their turn must make a constitution saving throw, taking 1d6 cold damage, halved if they succeed. Creatures who fail the roll also have their movement reduced by 10ft 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 damage increase by 1d6 for each slot level above 3rd.