Wool blankets are overlooked far too often as a great source of reliable insulation.

the old surplus blankets are great pure virgin wool.

1 hint:

Wash in cold water with wool detergent.

Then put 3 cups of hair conditioner in the rinse cycle with the liquid fabric softener, your blanket when airdried will be 80% softer and less itchy.

Wool is warm when wet but heavy.
It is naturaly fire resistant.
It is cheap and can be made into other articles.

Good stuff.

I recommed the old military surplus blankets with a tight weave. No particular country they are all good.

Mike