HETEBOTHERMY IN HOMEOTHERMS 



IRVING: Well, there certainly must be improved sensitivity; 

 that would be the conclusion from the fact that they appear better 

 able to monitor what is going on outside. That is, they are more 

 observant of minor temperature changes in exposed skin areas such 

 as the face and fingers. This is not a reduction in sensitivity or 

 simply hardiness. Rather, along with the suppression of pain or the 

 suppression of the impression of pain, there is apparently a more 

 refined observation of the local temperature condition of the skin. 

 As yet, we have not successfully demonstrated that sensitivity is 

 retained at a better level in the cold adapted skin than in the warm 

 adapted skin. So far we have only used these sensory tests with 

 people that were unadapted to cold. There are other tests that indi- 

 cate that the temperature sensitivity is retained better in the cold 

 skin after the people have been accustomed to exposure. 



EAGAN: From the figures you have given on Eskimos, there is 

 a suggestion that their adaptation is an ability to maintain higher 

 peripheral temperatures, so that we cannot say that this is in any 

 way related to peripheral heterothermy as being an economical type 

 of adaptation. 



IRVINGj Well, you have to qualify the statement and say which 

 Eskimos you are talking about. As Mr. Miller has shown, there is 

 a real difference between men and children, and yet they are all 

 normal components of the population. In addition, he also observed 

 that the skin of the Eskimo children did cool more rapidly and to a 

 lower temperature during the period of exposure than was true of 

 any of the adults. 



EAGAN: Children do seem to withstand very low hand tempera- 

 tures even here in Fort Wainwright. 



IRVING: I do not know whether it is true of all children or not. 

 We do not dare to ask parents to lend us their children for experi- 

 ment, but we have no compunction about asking the Eskimo children 

 to cooperate. They enjoy it. 



EAGAN: Glasser's work with habituation or repeated presenta- 

 tion of an extreme cold stimulus shows that there is a change in 



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