Equipped for grueling runs and high-intensity training, the SmartWool Men's PhD Ultra Light Shirt enhances thermo-regulation with its breathable mesh panels and merino wool blend. Merino wool naturally wicks moisture off your skin to promote evaporative cooling, also preventing the growth of odor-causing microbes. Ultimately, this means you'll stay pleasantly cool during heart-pumping workouts, all without the funky smell of a pure polyester training top. Other comfort-enhancing features include smooth flatlock seams and raglan sleeves for full range of motion. Plus, the 360-degree reflectivity boosts visibility when you're running in darker hours and low-light conditions.