It is not all a matter of conductive heat loss. A major cause of lost heat is blood flow. The surface of the body is maintained at a lower temperature when trying to retain heat. Blood flow works against this. The blood flow in fat is low. The blood flow in exercising muscle is high. If that muscle is close to the surface of the body, then a lot of heat will be lost. One reason that young, muscular men do poorly in cold water is that they are heavy (fat is more buoyant than muscle) so they have to swim more actively to keep their head above water and that drives more blood into their muscles which are close to the skin and that results in rapid cooling. (There is a lot of blood flow in the scalp so it helps to keep the head out of the water) A fat guy just floating along does better. On May 21, 2010, at 8:14 AM, PeterO wrote: > Given the conductivities involved, I'm finding it hard to grasp how > human > subcutaneous fat, blubber, whatever, is a sufficiently good insulator *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Fri May 21 2010 - 18:00:01 PDT
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