Get that blanket away from me! Argh!

Why do people always feel a need to cover sleeping people with a blanket or something?

No, it did not happen tonight, just came into my mind because it was too hot in the room anyway. I am rarely in a position where people can attack me with blankets while I sleep, but when I am they always do. Don't people realize that if a person went to sleep or passed out without a blanket that might be because the person didn't want one?

I usually need less heat when I sleep than when I am awake; do other people work in a different way? Waking up because of excessive heat feels awful to me; waking up because of cold, finding a blanket and going back to sleep is not a problem at all. Maybe the next time I am about to fall asleep in human company I should put a sign on myself: "Please do not cover".

Still, the question stands: what is it that makes people want to cover sleeping people? Do they really think they are cold?