text: in cold water, why does hypothermia set in faster if you move around.? i have heard that in freezing water hypothermia can set in faster by being active rather than remaining stationary.  why is that?  i asked this question here because i am looking for some better answers to my questions. thanks i understand your dilema.  activity produces heat; but the amount of cold 'gained' by moving around in extremely cold water is much much more than the little heat produced by the activity.  leading to faster reduction in temperature, leading to faster hypothermia.