What percent of body heat is lost through your head?

I gotta go with the NY Times on this one. It would seem that it's not entirely true. Body heat escapes through any exposed surface. The larger the surface, the more heat that escapes. If you have less hair, naturally, you'll lose more heat through your head (I happen to shave mine, so I know!) http://www.nytimes.com/2004/10/26/health/26real.html