Freezing Mist

You summon a chilling fog in a 10-foot-radius Sphere centered on a point you can see within range. The area becomes heavily obscured. Each creature that starts its turn in the fog must make a Constitution saving throw, taking 2d4 cold damage and having its movement speed is reduced by 10 feet until the end of its turn on a failure. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it, or until any source of fire damage passes through it. The fog lightly coats surfaces with ice, making any space it touches the ground in difficult terrain.   At Higher Levels. When you cast this spell using a higher level spell slot, increase its radius by 10 feet and its damage by 1d4 for each slot level above its base level.