Amid all this, Dr Ashcroft develops an amusing recurring theme about the willingness of physiologists over the years to perform experiments on themselves in order to advance their understanding of the limits of humanendurance.
These stories, and others concerning extraordinary feats in extreme cold, at great depths underwater, in sporting arenas and in outer space, are the starting points for Dr Ashcroft's careful explanations of how the human body copes at the limits of endurance.
And most of all, we are honored to be in the presence of men and women whose lives are a testament to the endurance and the strength of the human spirit -- the inspiring survivors.