INTRODUCTION 



self-evident that knowledge gained from studies of native popula- 

 tions selected genetically through the centuries for life in the 

 Arctic might conceivably have little applicability to the behavior 

 of a population of greater size and concentration suddenly moved 

 into this environment. 



Cold is a stress. How much it results in a unique response by 

 the body and the degree to which it resembles other stresses must 

 be left to the physiologists for elucidation. They have already 

 established that acclimatization to cold entails greater heat pro- 

 duction through an elevation in metabolic rate as judged by in- 

 creased oxygen consumption. This is believed to be mediated through 

 the endocrines in a highly complex, and as yet incompletely under- 

 stood manner (Hart, 19 58). These facts have pertinence for anyone 

 interested in host- parasite interactions because of the well docu- 

 mented contributions host metabolism makes to determining health 

 or illness from an infectious agent. Dubos' book, The Biochemical 

 Determinants of Microbial Disease, (19 54), is a milestone, and 

 since its appearance, numerous publications have expanded the 

 literature. 



Mammals exposed to cold can be expected to maintain normo- 

 thermia unless there is excessive heat loss. Hypothermia is probably 

 the consequence of too little heat prcxiuction and too great heat 

 loss. The investigator must constantly be preparecTtodisoriminate, 

 therefore, between effects in normothermic cold, exposed animals 

 and those found in hypothermic ccld exposed animals. The literature 

 contains all too many examples of work in which these distinctions 

 were not made. 



The major question confronting us is: Does cold exposure in- 

 fluence detrimentally man's ability to combat infectious diseases? 

 This question raises many more. What diseases? What men? How 

 much cold ana for how long?It is obviously difficult to answer these 

 questions, particularly with man as the experimental subject, except 

 for the most unusual circumstances such as those Sir Christopher 

 Andrewes has used so imaginatively in his studies of the common 

 cold. To a highly limited extent, it might be possible to utilize human 

 volunteers for experimental infection with a few Diseases against 

 which highly therapeutic agents are available. So far as I know, 



