Base layers are crucial outdoor gear.
When you're winter camping, though, you'll want heavyweight layers to trap that warm air. Variations of temperature, humidity, and terrain make it tricky to choose the right skivvies, but our base-layer breakdown will help you nail it more often than not. The top has a silky feel and is styled like a bike jersey, making it outer-underwear you can use all year. Since less material touches your skin, heat readily escapes. Unlike polyester, which absorbs and then disperses water, polypropylene is hydrophobic, meaning it won't load up like a wet mop.