I've read Tom Austin's article in the Iron Butt magazine concerning hot weather LD riding... http://www.ironbutt.com/ibmagazine/ironbutt_1002_62-66_Hot.pdf I'm doing a BBG/50CC which will take me across the I-10/I-8 corridor later this week. Its forecast to be HOT, to the tune of ~115° or so. I will have a choice of a mesh Tourmaster jacket, or an Aerostich Transit (leather) jacket. I also have a pair of LD Comfort sleeves. I'm not sure weather to wear the Transit with the sleeve cuffs open, or the mesh with an under armor short sleeve shirt with the LD sleeves? Thanks for the advice.