I prefer natural fibers because I think they breathe better and keep me better regulated. And as someone that works outside year round in the Midwest, layers are what work. I have found that keeping my chest the warmest, it helps keep the rest of me warm as well.

Just don’t sweat, or if you do, be down to the lowest layer possible. And when you go in, get down to the lowest layer to air out the top layers and to help regulate your body heat.