A friend gets shocked horribly all winter when wearing any manufactured fibers, like nylon, fleece, polyester, etc. He's looking for a warm winter jacket that's made of all cotton. Wool isn't an option either. I think down would be warm, but all down jackets seem to use polyester to contain the down. Optimally, this would be a jacket that would keep him reasonably warm in temperatures down to the mid-30's. Does anyone have any ideas for me?