I wear this shirt constantly
I LOVE this shirt. I have worn it hiking in cold temperatures on top and worn it during the dead of summer in the lowcountry of South Carolina. It works perfectly in both environments. In fact, I wear it so much, my wife has asked me whether I ever take it off (I do; I sometimes shower). I am 6'0" and 157 lbs. I ordered a medium, and it fits perfectly.