Prestigious Physiological Society lecture at Keele

Posted on 15 May 2015

The prestigious Physiological Society GL Brown Prize Lecture, Extreme Threats by Professor Mike Tipton (University of Portsmouth) will take place at 3pm on Wednesday 27 May in the  Westminster Theatre.

Since the iconic picture, “Earthrise”, was taken from Apollo 8 as it orbited the moon and our planet rose above the horizon, we have considered our world a “blue planet”, an oasis amongst otherwise inhospitable and indifferent spheres. However, the idea of an Eden-like home that we have evolved to be in harmony with, that nurtures us as we care for it, is some way from the truth. On one side of the ecological coin we have the damage we do to our world by our existence. On the other side we have the fact that 70 % of our planet is covered in water, with an average ocean depth of 4,000 m. Light penetrates up to about 80 m into water, so most of our planet is in permanent darkness; the rest of it is in intermittent darkness with day and night. Only 15 % of the surface of the Earth is not water, desert, ice or mountain. For humans, a sub-tropical, 1-G, low altitude, air-breathing homeothermic animal, most of our home represents a hostile place.

Whilst we can demonstrate acclimatisation to heat, cold and altitude, if constrained by these capacities we would still inhabit a very small portion of our planet, close to our equatorial origins. Instead, it is our behaviour, underpinned by intellect and invention, that has allowed us protect ourselves, recreate our desired macro and microclimates, and thereby visit or the rest of the planet and the Worlds beyond. So it is that wherever in the world you take the measurement, if resting humans report being “comfortable” they will have a deep body temperature of 37 °C and mean skin temperature of 33 °C, just as they would have had living naked in their ancestral home with its air temperature of 28 °C.

The technical abilities that have enabled us to inhabit the rest of the planet have also made us very dependent on that technology, as well as limited the extent of our physiological adaptation. This creates problems; when things go wrong we often have to fall back on our primitive, unevolved, physiological defences. The consequences of their limitations include hypoxia, drowning, hypothermia, cold injury, hyperthermia and barotrauma. These pathophysiological threats can arise in natural as well as man-made environments: from mountains to space craft. In his lecture Professor Tipton will discuss some of these threats: their origins, consequences and ways of ameliorating them.