"Men's On® Climate Shirt: The Men's On Climate Shirt is a long sleeve half-zip running shirt built for cool-weather training runs, morning hikes, and brisk walks where conditions can shift on you. The quarter-zip closure lets you manage ventilation as your effort changes, and the woven fabric with a multi-dimensional surface actively wicks sweat away from your skin so you stay drier across a range of temperatures. If you run early mornings or after dark, the reflective details keep you visible without adding bulk.What makes the Climate Shirt worth a closer look is how the construction supports movement. Spiral dart elbows and a contoured back seam follow the natural motion of your arms and torso, reducing restriction when you're pushing the pace or reaching on a trail. Thumb holes extend sleeve coverage over your hands when temperatures drop and keep the cuffs from riding up. A side zip pocket handles the essentials - keys, a card, a gel - without getting in the way. The shirt is built to hold warmth when it's cold and release heat as your body temperature climbs, which makes it a practical layering option for variable conditions rather than a one-note cold-weather piece.Why Our Fit Experts Love It""I took the Climate Shirt out on a cool morning run and it handled the temperature swing well - warm at the start, not suffocating once I got moving. The thumb holes kept my cuffs in place the whole time, and I appreciated having the zip pocket for my key without needing to carry anything else."" - Dave, Road Runner Sports Fit Expert, San Diego, CAWho It's Best ForThe Men's On Climate Shirt is a strong choice for runners, hikers, and walkers who train in cool or variable weather and want a moisture-wicking long sleeve that layers well without restricting movement. It works especially well if you head out before sunrise or after sunset and want low-light visibility built in. VIP Family members can take the Climate Shirt for a 90-Day test drive with our Perfect Fit Guarantee."