29123 Arcteryx Men's Cormac Hoody The summer sun can be fierce, and as you climb, UV levels increase. The Cormac Hoody is specially created to help shield climbers, hikers - anyone seeking mountain adventure - from the sun and keep them comfortable on the move. One of Arc'Teryx's lightest fabrics, the Ostria polyester is airy and exceptionally comfortable. A brimmed helmet-compatible hood protects the face, thumb loops hold sleeves in place, and low-profile seams ride comfortably under a pack.