I brought an Indian blanket along with me on vacation. Yes, one of those garish heavy wool blankets. In size more a large throw than a blanket. It covers me with room to spare, but not much.
Anyhow, I find that lying on my back beneath the Indian blanket I sleep like a log for hours, and awake still lying flat on my back. Whereas at home I'll toss and turn, and more often than not awake lying in some uncomfortable position on my side. Interesting.