Thanks. I rode about an hour wearing it yesterday, air flow is really good. It was in the upper 80s; not a cloud in the sky. Maybe it's just in my head, but it did feel cooler (while moving) with the jacket vs without. It could be because the sun isn't shining directly on my skin, kind of like being in the shade? At any rate I like it a lot, and will be wearing it from now on. I haven't really been worried all that much about riding in just a t-shirt. A friend recently went down trying to stop when a tractor pulled out in front of him. He got some road rash on his arms that a jacket of any kind could have helped.