NUNGESTER 



physiologically; and 7) pathogenic microbial flora of the host or his 

 environment at the time of exposure to low temperature. 



To suppliment all this, the question might be asked, does an ex- 

 cessive heat transfer from the host to his environment affect host 

 resistance to infectious diseases? As a starting point, we should ask 

 ourselves what has been decided as to the effect of low ambient tem- 

 peratures on the resistance of man to infectious diseases. As Dr. 

 Berry recalled, many of his elders as well as his country doctor all 

 warned against wet feet (and heat loss). At that time, these people, 

 being fine Texans, believed that exposure to cold did predispose to 

 upper and lowerrespiratorytractinfections. Of courseproof of such 

 widespread beliefs is hard to come by, as Dr. McClaughry and Sir 

 Christopher have stated, Goldstein (1951) has claimed that extreme 

 cold is a "potent stress factor in bringing about the common cold". 

 Troisi et al. (1953) found a higher incidence of upper respiratory in- 

 fections in 66 men working in cold rooms of meat preservation 

 plants. Andrewes has shown us that colds are more prevalent in 

 temperate zones in winter than in summer, and as we know, the rate 

 of change of heat loss can be quite marked in these zones. The 

 chances for irregular cooling of body surfaces may be significant. 

 But I think we would all agree that a definitive answer has not yet 

 been derived. 



It would appear that we need more epidemiological evidence on 

 the effect of increased heat transfer from the host and on suscepti- 

 bility to infection. Experiments in the future should attempt to cor- 

 relate not cold as such, but rather, the various factors associated 

 with general or local loss of body heat with the incidence of infection. 

 And what are these various factors ? If only some knowledge as to 

 what measure to use other than rectal temperature or ambient 

 temperature were available. Perhaps then we would have a more 

 direct measure of what exposure to cold does to the host, and by this 

 many of the variables which now confront us might be reduced con- 

 siderably. 



Turning now to another aspect of the symposium, we might recall 

 the reports on experiments with animals in which host resistance 

 was altered by exposure to low ambient temperatures. Conclusive 

 data was presented by Dr, Previte and Dr. Miraglia which showed 



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