The Patagonia Capilene Cool Trail Long-Sleeve Shirt pairs a recycled polyester wicking structure with TENCEL softness so the fabric moves sweat away without the stiff, clammy feel that builds up on sustained efforts. The HeiQ Mint treatment is plant-based and holds up through repeated washes without degrading the way synthetic anti-odor finishes tend to. What Our Gearhead(R) Experts Are Saying:"I've worn this on back-to-back trail days without it turning into the shirt I don't want to be near. It moves sweat off fast enough that it doesn't stay damp on the climb, and it doesn't smell like effort by the time I'm back at the trailhead."