When the fan operates in a closed room, the motion of the air molecules increases. The increase in the motion of the air molecules increases the rate of evaporation of sweat from our body. Due to this evaporation, we feel cool. There is no actual fall in room temperature. Rather, the room temperature increases slightly due to increase in kinetic energy of the air molecules.
Blankets can be used to protect the Ice from Melting
A blanket traps a large amount of air between its fibers. When we cover our body with the blanket, the trapped air prevents the heat transmission from our body to the cold surrounding. As a result, we feel warm. Similarly, when we cover the ice with the blanket, the trapped air of the blanket prevents the heat from outside surrounding to flow into the cold ice. As a result the ice gain no heat and hence remains frozen.
Animal curl into a ball during Winter
We know that the amount of heat radiated by a body is directly proportional to the surface area. If the surface area is reduced, heat radiated is also reduced. For a given volume, the surface area is minimum when it is a sphere. Hence, to reduce the heat radiation from their bodies by reducing the surface area, the animals curl into a ball in the winter.
It’s actually due to the motor heating up as it spins the blades. For temperature to increase due to air movement, you’d need wind speeds of 1000+ km.
Considering the ice-Box with rotating fan in it where the driving motor is isolated from ice box and only rotating fan is inside the box. To observation temperature still increases. Also tried rotating dumb cylindrical mass that has no airfoil but moves air inside due to drag. To observation temperature in box still increases.