Evolution

There is no such thing as a warm blanket (except if it it coming out of the dryer). If you put your hand on one blanket or another, you will feel a difference in texture, perhaps, but not temperature. The warmth you are alluding to is the warmth escaping from your body and trapped, with different degrees of success, by said blankets. Yet, we still refer to some blankets as warmer than others. No wonder I can't sleep.