Not all your body parts need to be warmed equally — since they're further from your core, your arms need a bit more insulation. This jacket has a cotton and nylon shell that breaks wind and keeps your chest protected from the elements but still provides room to breathe. Its sleeves are lined in cotton and polyester, giving you an extra layer of heat, and providing warmth where you need it most.
Shell: 72% cotton, 28% nylon
Body/Sleeve lining: 60% cotton, 40% polyester