DIFFICULTIES OF EPIDEMIOLOGICAL STUDIES 



of the purposes is to investigate these properties we are talking 

 about and about which we really know so very little, particularly 

 in the human. 



McCLAUGHRY: It occurred to me, also, that your descrip- 

 tion of the situation of the patient with bacteremic shock also 

 bears on this question of stress, because bacteremic shock 

 is one of the things which suppresses those functions. In one 

 sense, you have the anesthesia, anti- shock, and the anti- stress 

 state established by physiological and pathological mechanisms. 



BLAIR: That is quite right. It is the pathologic state, the 

 comatose state, essentially. The only thir^ I am interested in, 

 of course, is controlling the reflex mechanism; that is, shivering. 

 In elective situations, we use anesthesia to depress this, and, 

 of course, anesthesia is a tremendous poison. It poisons a lot 

 of things besides the skeletal muscles. 



SCHMIDT: I would like to make reference to some work we 

 did here in Alaska. Our original aim was to determine the in- 

 cidence of respiratory disease here at Ladd Air Force Base. 

 We had about two thousand subjects. It occurred to us that it 

 might be possible to investigate the influence of cold exposure 

 on the incidence of infection. Accordingly, in taking the his- 

 tories on these men, we started by asking them if they worked 

 outside or inside. This approach proved to be of little value, 

 because even though their duty stations might have been out- 

 side, the men were clothed to the extent that they could not be 

 considered to be cold exposed in the sense of being chilled. 

 We eventually grouped the men according to their squadron ac- 

 tivities, thinking that cooks and bakers, for instance, would be 

 less likely to encounter cold exposure than would field main- 

 tenance crews. About one third of the 1,985 men studied were 

 in squadrons which we considered would have a higher exposure 

 index. We were unable to demonstrate any significant differ- 

 ence in the incidence of upper respiratory infection attributable 

 to cold exposure, I think we ran up against a stone wall in trying 

 to determine, with any degree of certainty, whether these men 

 were actually cold exposed. 



21 



