You unleash a burst of frost that envelops an object no larger than a 5-foot cube or a creature within range.   If you choose an object, it becomes frozen solid for 10 minutes. This could freeze a door or lock in place, making it difficult or impossible to open. Or it could freeze a weapon, object, or tool, making it temporarily useless. The ice has an AC of 13, 20 hit points, and vulnerability to fire damage.   If you choose a creature, it must make a Constitution saving throw. On a failure, it takes 2d6 cold damage, and has its speed reduced by 10 ft.