Conquer freezing temperatures with this SIMIYA two-piece thermal underwear set, engineered specifically for men who require a reliable 3XL base layer for outdoor work, winter sports, or daily commutes. This high-performance set features a sophisticated blend of 92% microfiber and 8% spandex, creating a 4-way stretch fabric that contours to your body for a streamlined fit without restricting natural movement. The interior is lined with an ultralight, opaque fleece layer that traps body heat effectively while remaining breathable, ensuring you stay warm without the bulk of traditional winter wear. Both the long-sleeve top and matching pants are designed with reinforced flat-lock seams and a tagless interior to eliminate skin chafing and irritation during extended periods of activity. Functionality meets durability through thoughtful design details such as a practical fly opening in the pants and elasticized cuffs on the sleeves and legs that prevent rolling, effectively sealing out cold drafts. This pull-on set serves as an essential foundation for layering under uniforms or heavy outerwear, providing consistent thermal insulation throughout the coldest months. Easy to maintain with standard machine washing, these thermals retain their shape and soft texture even after frequent use. Whether you are hitting the slopes or working on-site, the SIMIYA thermal system offers the perfect balance of modern aesthetics and heavy-duty protection against the elements.