I have worn the underarmour tactical line when in uniform. I have both the cold gear and the heat gear, and both work equally well for the stated weather conditions. I still wear their stuff when I'm back in the states, but I no longer wear it while deployed after seeing what happended to a buddy of mine when his humvee was hit by an incenderary IED....With out getting to graphic, lets just say that the polly in the shirt melted INTO his skin. Now I wear cotton when going outside the wire, but I hear that underarmour is coming up with a new fire resistant fabric, so I might switch to that.