During that glorious 63F-every-morning commute week there were a couple of days in which I arrived at work with barely any sweat after my usual 12-13 mile ride. I rode with my Chrome Industries backpack for easier filtering, because everyone was saying traffic would be hell that week (Papal Visit). I only had my usual polyester t-shirt and shorts. Some fellow commuters had arm/leg warmers or tights under the shorts - I knew i'd burn up if I put on more layers.