The simplest, most-effective winter barrier money can buy is delivered in a shell. But why not just don a trash bag when it’s wet, or a plump parka when it’s cold? Because your body needs to breathe, brothers and sisters. And if you’re actually snowboarding-not sitting in the lodge-then you know that sweating when it’s fifteen degrees out is no myth. Shells let heat and moisture permeate outward, yet dam water from seeping in-even down to the tech, waterproof zippers.