Originally Posted by ph0rk
basically they are advocating evaporation, which is pretty much the only way to cool yourself once the air temperature is higher than your skin temperature (roughly 93 degrees, not 98).
See this following article from the Ironbutt Magazine: http://www.ironbutt.com/ibmagazine/I..._62-66_Hot.pdf
Depending on your jacket, you'll probably need a vent or two open to get the evaporative effect, regardless of what the LDComfort people say.
Hey, ph0rk, thanks for posting that link.
That made for some interesting reading, and now it makes sense to me why I usually felt like I was cooler underway with a crudely vented patrol jacket than with my mesh jacket.