Under Armour’s cold-weather fabric technology is called ColdGear.
ColdGear is designed for training and performance apparel used in cold conditions. Under Armour describes it as a thermal-baselayer technology that combines insulation with moisture management, helping retain warmth while moving sweat away from the skin. The close-fitting construction is intended to work as a base layer beneath other clothing.
The technology is associated with dual-layer fabrics, with an inner side designed to help hold warmth and an outer side that helps transport moisture outward. Under Armour has also marketed ColdGear garments with stretch, compression fits, ventilation, and odor-control features. Specific construction varies across products and generations, so “ColdGear” is best understood as a branded technology family rather than one single fabric formula.
The most common mix-up is HeatGear, which is Under Armour’s warm-weather line intended to help athletes feel cooler and drier. Storm is a water-resistant product technology, while RUSH is an infrared-based performance technology. ColdGear’s defining association is cold-weather warmth, making it the canonical answer.