For training and operations in extreme temperatures, count on Under Armour undergarments to help you keep your edge. The brand’s base layers are designed with flat seams to reduce friction and fabric technology to help you stay cool, dry and comfortable at all times. Ideal for cold-weather operations, Under Armour offers styles that trap heat while remaining breathable. You can also find options designed specifically for hot climates with moisture-wicking, temperature-regulating fabrics to keep you cool and dry. Some styles have a compression fit to help with performance and recovery after you work out. With leggings, boxers and shirts to choose from, Under Armour underwear has you covered.