SUMMARY OF SYMPOSIUM 

 W. J. Nungester, M. D. 



University of Michigan 



Medical School 



Ann Arbor, Michigan 



Years ago, the great naturalist Agassiz counselled, "Go to Nature, 

 Take the facts into your own hands. Look and see for yourself." 

 During the past three days, we have followed this sage advice. But as 

 we have looked, perhaps we have not seen with complete clarity, for 

 the problems are complex. Yet those responsible for this symposium 

 have given us a widely arranged spectrum of subjects for discussion 

 which have afforded us the opportunity to 1) "go to Nature" and look 

 at the effects of cold on the incidence of naturally acquired infections 

 in man; 2) "take the facts in (our) own hands" and see for ourselves 

 the effects of hypothermy on experimental infection; and finally, 3) 

 hear reports on the search for mechanisms by which host-parasite 

 interactions are affected by hypothermy. 



In examining the data on the effect of cold on naturally acquired 

 infections in man, we are confronted by complexities, as was clearly 

 pointed out by Dr. Berry, Dr. McClaughry, Dr. Babbott, and Sir 

 Christopher Andrewes, In determining whether or not lower ambient 

 temperatures affect host- parasite relations, ithas been shown that a 

 number of factors must be considered, among which may be listed 

 the following: 1) the temperature gradientbetweennormalbody tem- 

 perature and the environment; 2) moisture or wind which increase 

 the transfer of body heat to the environment with a local and general 

 cooling of the body; 3) non-uniform cooling on parts of the body which 

 may have peculiar physiological effects, as demonstrated by Mudd 

 et al, (1921) ; 4) since we know from Pfluger's Law that the physio- 

 logical response is related more directly to the rate of change of 

 the stimulus than to the strength of the stimulus, rate of change of 

 body temperature is significant; 5) physiological conditions of the 

 host affecting heat transfer from the skin as peripheral dilation (al- 

 cohol) or the effects of local or general cooling of the body as car- 

 dio vascular diseases, endocrine disturbances, and so forth; 6) pre- 

 vious acclimatization of the subject -to cold, whatever this means 



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