Cool in the summer, warm in the winter, great to throw on right after a sweaty ride. The ultra wicking of Pearl's proprietary fabric dries up that hard-earned sweat and instantly makes you feel cooler and more comfortable. Keep one in your car or dry bag for a quick change. Also great for running, working out at the gym, you name it. I bought a bunch of these, way more than I need, so I'm parting with a few. Thanks for looking!