I totally agree that cold is better. If it really is too cold, one can always add layers or a blanket, but if it's to hot ...

One point that intrigues me: I quite often find that the temperature on a plane is fine until after the meal service has finished and the lights are turned down, when it appears to become warmer. Do the crew actually increase the cabin temperature when they think the majority of people will be sleeping (definitely not a good idea for me!) or ... is my metabolism working overtime because of all of the food and drink I've just consumed?