While Mark does have good stuff on his site, the vbl stuff needs work, because some of the physiology described is wrong. The warmlite stuff is junk.
A rebuttal to the warmlite article:
http://tinyurl.com/3b9dr4Here is a good article on thermoregulation:
http://www.backpackinglight.com/cgi-bin/backpackinglight/00184.html