Every little bit of warmth is precious when you're in the alpine. Black Diamond designed the Forge Hoodie to retain warmth on ice-cold alpine walls, wind-blasted ridges, and frigid transitions. While incredibly warm, down can be tricky to wear in a storm because it loses its insulating properties once it gets wet. Black Diamond put a DWR treatment on the 700-fill down and the Pertex Microlight fabric for some protection from light precipitation. Underarm gussets give you a wide range of motion on the ascent, and the whole jacket stows in its chest pocket with a carabiner loop so you can easily clip it to your harness or stuff it in your pack when the sun pokes out.