Loud Radiator Fan
I stopped at a red light yesterday and was thinking to myself, "that is one loud truck next to me". The truck pulled away, but the noise stayed. Open my window and heard that it was my car. I pulled over and opened the hood and the radiator fan was going nuts. It might have been normal if it was summer, but it's like 10F outside right now and the engine temp was at about 180F. I also felt some power loss on acceleration before I pulled over. I turned the car off and it has been fine since, but I'm kind of worried.
What does this mean? Is my water pump or thermostat going bad? Car has 50k miles.