Just the other day I went for a long ride on the highway on a very hot day. I usually wear my gear but because it was so hot decided to just wear street clothes (long sleeve button up shirt, jeans and boots). After about 90 minutes at high speed the beating I was getting from my shirt flapping in the wind was driving me crazy. Plus I was roasting under the blazing sun. I realized that my jacket provides just as much protection from the elements as well as cooling ventilation. Traffic jams, however, are another story.