There is an interesting popular article on physiological consequences of long expeditions in extreme environments in today's issue of Current Biology. It is a short and accessible overview of challenges human body is facing under such conditions. For those who do not have access to academic journals' subscriptions, feel free to write me a PM.
Halsey & Stroud 2011. Could Scott have survived with today’s physiological knowledge? Current Biology 21(12)
Abstract: In 1911, members of a British expedition walked across the Antarctic to the
South Pole, but in the punishingly hostile environment, retracing their steps
back to the edge of the continent proved fatal. Over the last 100 years,
knowledge about human physiology has greatly increased and, on the
centenary of this most extreme of all journeys, this essay explores the true
extent of the physiological stress experienced by the men involved and whether
their fate was inevitable.
Link