Martyn
Thanks for your reply. I agree that hard linking to temperature is wrong and that we must learn to recognise signs and symptoms. This is why I wrote the following in my article (my bolding for the purpose of this reply):
"The pitfall with a categorisation based on body core temperature is that its not possible to monitor internal body temperatures in the field (even if you are very good friends, using a rectal thermometer while on the slopes of Ben MacDui is not practical). A drop in core temperature will affect every part of your bodys system so we must look for the signs and symptoms of these changes".
Which is why I then go on to relate signs and symptoms in terms of woolier 'mild', 'moderate', 'severe' and 'deep' hypothermia. But even to that I added the following caveat (again my bolding here for the purposes of replying):
"It should be noted that fitting signs and symptoms into corresponding classifications of mild and moderate hypothermia are largely based on experiments involving the immersion of subjects into cold water, while the categorisation of the signs of severe and deep hypothermia come from individual case histories, all of which have shown some variation, not least in mortality rate.
What you might observe in your companions on a wet and windy day in October on the slopes of Snowdon or Mount Washington, could be different to the above. Experiments suggest maximal shivering occurs at a body core temperature of 35oC (95.0oF) but rescuers have reported no shivering in some hypothermia casualties at this temperature. Shivering normally ceases below 31oC (88oF) but has been recorded below 29oC (84oF). Unconsciousness normally comes between 33oC (91oF) and 27oC (80oF) but some patients have been verbally responsive at 26oC (79oF), a temperature at which others have died."
As for sticking to the "accepted medical definition", the medical profession can also be pragmatic; for example in Ch16 'Treatment of Accidental Hypothermia' of 'Medical Aspects of Harsh Environments, Volume 1. Textbooks of Military Medicine. Washington, DC: Borden Institute, Office of the Surgeon General, US Army Medical Department' (which is written by medical doctors) it states (my bolding):
"
To allow for the diurnal variation of one to two Centigrade degrees, a person is considered to be in a state of hypothermia if the core temperature is below 35oC. Obviously, medical officers should not view this threshold with the attitude that hypothermia does not exist when the core temperature is 35.5oC and therefore the patient is safe, whereas a core temperature of 34.5oC is diagnostic of hypothermia and the patient is in danger."
One of the authors of Ch16 was Evan L Lloyd, an Edinburgh-based consultant who wrote the book 'Hypothermia and Cold Stress' in the 1980s. While this book may be out of date in some respects, it is worth reading the introduction for its historical perspective.
In the introduction, the author also writes of non-medical profressionals making remarks or observations about hypothermia
"If clinical observations are made, the nonentity of the observer, at least in medical eyes, or the lack of scientific 'measurement' may mean that the information is dismissed as anecdotal or hearsay". Is history repeating itself on this forum?
A free copy of Evan L Lloyd's book can be had here:
http://books.google.co.uk/books?id=2Zc9AAAAIAAJ
The medical profession can also be inconsistent with the "accepted medical definition". For example, in Ch 17 'Cold Water Immersion' of
the same medical textbook 'Medical Aspects of Harsh Environments, Volume 1. Textbooks of Military Medicine it states:
"
The data are divided into three ranges of core temperature: mild hypothermia, 37oC to 33oC; moderate hypothermia, 32oC to 27oC; and severe hypothermia, 26oC to 18oC".
This chapter was authored by Lorentz E. Wittmers, MD, PhD, Associate Professor, Department of Medical and Molecular Physiology, and Director of Water Safety Laboratory, University of Minnesota School of Medicine.
But at the end of the day, let's not get bogged down in semantics and definitions.
Where we are in total agreement is about what is most important - being able to spot the signs and symptoms. And spot them early! I think even Ronnie would agree with this?
And Ronnie - the whole point of people doing research and writing it down is that other people can read it and learn from it. For instance, while Martyn undoubtedly has his own very valuable professional experience to rely upon, the majority of the knowledge provided by his medical training is down to the work of generations of doctors and researchers before him. No disrespect to Martyn but he is 'standing on the shoulders of giants' as it were. And as developments and advances occur, this knowledge is promulgated without every doctor having to invent it for themselves. I'm not saying reading is a substitute for your own personal experience but there is nothing wrong with being able to read about and benefit from other people's work and experience too. You can have read books and have experience, you know. They are not mutually exclusive.
I'm not trying to have the last word here and I'm sure Martyn will respond. I value our ability to discuss these matters here. I think we all benefit from it.
All the best
Paul