When you have to spend the night with the same shirt you've been grunting up the mountain in all day, then you'd best make sure it isn't going to stink. Using both merino wool and Cocona fabric, the Rab Men's MeCo 165 Hooded Top won't take on much funk even after multiple days of use. Both fabrics offer antimicrobial properties and excellent body temperature regulation and breathability, and the deep chest zip lets you get rid of excess heat quickly. The attached hood and thumbloops help lock heat in, and the flatlocked seams provide a comfortable next-to-skin fit.