Will I feel cooler?

Generally not. It's difficult to feel CoreControl extracting heat out of your body because you don't have temperature sensors deep inside your body; they are primarily on the skin surfaces. CoreControl pulls heat directly out of your core, via thermal portals in the hand, while most "cooling" technologies used today try to cool the body through the general skin surface. While using RTX you may not "feel" cool, but you will feel more refreshed and be prepared for what's next.