Those "Indian" blankets are probably Trapper, or Hudson Bay Blankets and are wool.
One underneath you, and one over top will keep the frost out.
You can achieve the same thermal warmth on a camping trip, with one warm body on either side of you....But the one underneath will start to squirm, causing a horrible nights sleep.
Oh...and another tip....Keep your lube at the bottom of your sleeping bag...That way you won't burn your fingers, when your forced to defrost it over the Coleman stove.
I'm not a Silk sheet guy, as you may have guessed...I'm more of a flannel guy...Or rubber if a bottle of oil presents itself.