Two UA innovations mean one ridiculously warm baselayer. Our latest technology—ColdGear® Infrared—holds heat so your baselayer warms up faster and stays that way longer. And all without adding any weight because the science is actually built right into the print. ColdGear® Thermo’s power lies in the unique hex-patterned design that traps pockets of warm air. This is your absolute best warmth for the weight.