I was wondering if anyone has an opinion about wearing Under Armor under their turnout gear. I would prefer to wear it because it dries out so fast compared to cotton but I am concerned about it being exposed to heat. I am mainly talking about the heat-gear shirts, I have worn it before without an issue but I would like to hear from some others about their experiences with it..
If you're wearing regular athletic Under Armor under turnout gear, you may want to re-think it.
Artificial fabrics like those in Under Armor can melt if the air space beneath your TOG gets too hot.
There's a concept called "Shrink Wrap Syndrome" that covers it.
Under Armor does make fire-resistive underwear, but that underwear doesn't wick sweat nearly as well as the athletic kind.
Check out the NFPA station uniform standards for more on this.