the best take i heard on this--from a Dr--was that the little
nastys in the water are "programed" to reproduce at our body
temp..at 98.6 they start to unzip their DNA..with nothing
around them except H2o they just keep unraveling into the
harmless base chemicals they are made from..the stuff that
survives in really hot water--like at Yellowstone Park--does
not have us on their food chain..