The Anatomica L/S Crewe by Icebreaker is great for any situation that makes you sweat. It has light material qualities. This item is perfect for mountain hikes in the summer, ski tours in spring, and training runs in fall. This long-sleeve consists of mixed Merino wool and synthetic fibers, giving it a fine stretch. You can wear this shirt solo or under other layers of clothing. Unlike cotton, Merino underwear stays warm when you get sweaty. And unlike synthetic fiber variants, no unpleasant odors appear.