Help! I´m looking for recommendations for women´s lightweight jackets/covers for those days when the sun is strong. I try to ride super-early in the a.m. (as soon as it´s light enough to be seen), but as the day goes on, the sun just saps my strength. I´ve not worn anything but short sleeves because I´m on thyroid meds and really susceptible to the heat . Obviously, I need to cover up better than I have been, so any suggestions would really be appreciated. Thanks in advance!