UA is the name of a brand, there are others less expnsive that work better I think. I like the silk heavy weight stuff and it keeps you warm, UA doesn't, it keeps you dry just like being infront of a fan. You definetly need something on top of it to hold the heat in. Anything that wicks moister away that fast will make you cooler.

I have UA/others/silk and polypropelene. All works well and I use it all. Just start collecting. Others and polyprop are the best value and work very well.

Do you stand hunt? I put a black ergo rubber mat on the base of my stand works just like black top when the sun hits it. Keeps me quite and warm.