I work in public safety, and I tried a couple of these out to see how they would work as undershirts under my uniform. My first day wearing one it was put to the test, as I got very hot and sweaty shortly after arriving at work. These shirts are awesome if you work public safety and have to wear body armour or hot turn-outs. The fit is good, no stretchy neckline, and the sweat doesn't stick to your body. Highly recommended.