EFFECT OF FUR AND CLOTHES 273 



treat with caution places where the temperature reaches 85 F. The 

 men work nude, pour with sweat and drink enormously, and work 

 so leisurely that probably an hour or two a day is the real period 

 of active work. A mine inspector who entered such workings in 

 his ordinary flannel clothes quickly reached a body temperature of 

 103 F. and could hardly walk for breathlessness. The body 

 temperature slowly rises as the regulatory mechanism reaches the 

 end of its tether. This happens at 88 F. in an atmosphere satu- 

 rated with water vapour (Haldane). Even in air saturated with 

 moisture at 88 F., evaporation of sweat is active owing to the 

 higher temperature of the skin. Thus while at 32 F. 1 c. ft. of 

 air takes up 2- 13 grains of water, at 60 F. it takes up 5-77, at 80 F. 

 10-98, at 90 F. 14-85, and at 99 F. 19-28. The working efficiency 

 of mines and stoke-holes obviously can be enormously increased 

 by the circulation of dry air. By such means at Pendleton Mine 

 work is done at 93 F. In dry air a man can sit for some minutes 

 while his dinner cooks in an oven beside him, i.e. at 100 C. 



Zuntz and Schomberg estimate that a resting soldier weighing 

 70 kg. produces 1-2-1-3 Cal. per min., while marching with a load 

 of 31 kg. he produces 7-73 Cal. per min. The heat thus produced 

 is sufficient to raise the body 1 C. in 8-7 min., and yet the trained 

 soldier, properly clothed and loaded in a suitable manner, shows 

 but a slight rise of temperature. 1 The importance cannot be over- 

 rated of supplying light, porous clothing to the soldier, and arranging 

 his load so that neither the respiration is impeded nor the balance 

 of his body disturbed. Hitherto, says Pembrey, he has been 

 " clothed in open defiance of common sense and physiological 

 principles. His tunic generally fits as tightly as possible, is made 

 of thick material and is fastened right up to the neck ; his waist is 

 hampered with a tight belt which interferes with abdominal breath- 

 ing, and other straps supporting valise and haversack still further 

 impede the movements of his limbs and body." His efficiency as 

 a marching mechanism is thus destroyed, his body becomes over- 

 heated in hot days and he in danger of sunstroke ; his heart and 

 respiration fail to maintain the extra demands put upon them ; 

 his muscular movements are not carried out with the maximum 

 economy. 



The danger of catching cold from damp clothes or beds is 



1 The normal rectal temperature after exercise on a warm day may be as 

 much as 101 F. The mouth temperature may vary as much as 3-4 F. from the 

 rectal, owing to cooling of the mouth by neighbouring skin and nose (Pembrey 

 and Haldane). 



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