What is the difference between under Armour HeatGear and ColdGear? Ideal for conditions between 55 degrees Fahrenheit and below, Under Armour ColdGear helps to keep athletes warm and comfortable so that they can stay outside and continue activity for longer durations. What temperature is under Armour cold gear for? Also called “second skin,” UA ColdGear Armour is brushed on the inside and smooth on the outside, as a lightweight layer. What Is ColdGear? Under Armour’s ColdGear is a lightweight, insulated layering technology that keeps you warm and dry in bitter conditions. Does Under Armour ColdGear keep you warm or cold?.What is the best base layer for extreme cold?.Does Under Armour HeatGear really work?.Is under Armour AllSeasonGear water resistant?.What is the difference between under Armour HeatGear and ColdGear?.What temperature is under Armour cold gear for?.