Ceiling fans do not lower or raise the air temperature in a room, they circulate the air. Using a ceiling fan in winter can help facilitate heating a room. The air on the floor is cooler, while the air near the ceiling is warmer. Depending on which direction your ceiling fan is spinning, it can either drag this air up (cooling the room) or push the warmer air downwards.
So, with the help of a heater, reversing the ceiling fan will pull the cool air up and push the warm air down the walls, helping to redistribute the heat to the floor. This provides an overall warmth in the room.