Some fans are designed with a switch to offer counterclockwise rotation (“forward mode”) and clockwise rotation (“reverse mode”). In the reverse mode, air is forced up toward the ceiling. This can help to warm the room by circulation of the warm air hovering near the ceiling down toward the floor. You need to be sure the fan is on low speed so as to not create a breeze. Consider this in rooms with a fireplace, wood stove, pellet stove or high ceilings.