I can’t find this anywhere. Not on their site, not googling this. And I don’t mean the really simple stuff. The simple stuff is that UA’s “HeatGear” is clothing you can wear in really hot heat or exercise and it cools you down, while “ColdGear” is normal clothing that keeps you warm in cold weather. That’s all anything says. But what the heck does that? I get the sense that it’s not just the fabric type. I mean is polyester a fabric that people put on in hot weather and it cools them down? Is it just the fabric types? Or is there some other science in the making of the clothes that does one or the other?
Don’t all clothes warm you in the winter and cool you in the summer? Presuming you’re not wearing a thick coat in the summer, that is? With nothing else to go on, I’d assume this is meaningless marketing speak and not science or technology at all.
But, like you, I don’t know for sure. There is garment technology that can wick away sweat for example, which helps both in the winter and summer. It’s possible they really have invented some new technical fabrics, but like I said, I’d doubt it until proven otherwise.
Descriptions of a HeatGear product:
ColdGear:
https://www.underarmour.com/en-us/mens-ua-coldgear-armour-compression-mock/pid1265648-600
Same materials in almost identical percentages. HeatGear product above weighs less, so less bulk. Has underarm ventilation. Mesh panel on back neck. UPF 30+ protection.
ColdGear has “dual-layer fabric with an ultra-warm, brushed interior & a smooth, fast-drying exterior”, “smooth, chafe-free flatlock seam construction” and then there’s obvious differences such as sleeve length and collar thickness.
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It sounds from the description that the ColdGear is thicker and fleecy. That may not be all of the technology, but it makes sense.