I have spent many summers in Phoenix, Vegas, Dallas, Houston, Lubbock, Del Rio and whole lot of other places where 100 degrees in the shade and 60 days of hardly a cloud in the sky is no exageration and have never gotten even a tan, let alone a burn on any part of my body covered by even the thinnest cotton t-shirt. I'm not denying what you say at all.... just pointing out why I find it so interesting. For all I know I may be somewhat immune to bruning this easily since I have lived in hot, sunny environments most of my life.