The Arc’teryx Thorium SV Hoodie confronts extreme winter conditions with oversized box-wall baffles filled with European grey goose down that maximizes loft and eliminates cold spots in temperatures where every degree matters. Strategic 80D 2L ePE GORE-TEX overlays on the shoulders and hood provide weather protection while remaining breathable, with moisture-resistant Coreloft synthetic insulation placed in critical areas where dampness typically compromises warmth.