I found some 100% silk yarn a few months back on clearance.
It's frrrreeeezing here on the East Coast, and I'm someone who is normally always ultra warm. I have the heat on tonight for the first time in my entire memory of living here.
Just knit myself a skull cap and nothing beats the softness/warmth! I'm curled up and toasty warm
Can't recommend enough, even if you are not the knitting type it's getting to be around winter-wear clearance time in the Northern hemisphere.