I'm not sure I agree with "poor conductivity" Here's my offer: I'll prepare a pan of 110-115*F water. You agree to dip your hand into it very very slowly so that there is no mixing or turbulence. I solemnly swear not to stir, move or otherwise disturb the pan or the water while your hand is in it, thereby preventing turbulent flow. I bet that in a few seconds you'll be able to tell me if any heat transfer is occurring... Along the same vein I find that a glass of beer left unattended (a rare error on my part, but not unheard of, sad to say) does warm up undesirably fast.