For the 15 years I have lived in Arizona I've been searching for great hot weather gear. Riding in the desert sun among the cacti can not only be uncomfortable, but dangerous (think, "getting lost on a trail and running out of water."). Having good, cooling gear is crucial. I was definitely doubtful when I saw the helios sun shirt - "long sleeve? what's with the weird hood?" were my thoughts. I eventually picked one up though. I just tried it out today - started the ride at 90 degrees and sunny and finished at 95. This shirt was EVERYTHING I HAVE BEEN LOOKING FOR! It's like they captured a cool Sun Valley breeze and sewed it into the fabric. It kept the sun off, provided cooling both when wet or dry. It was comfortable and light. So happy! one drawback, not pleased with the colors. The grey is good, but those others...oof. Can we get some non-1990's earth tone schemes in there? Great, great shirt for hot weather riding!