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On the Heating and Cooling of the Body by Local Application 



of Heat and Cold. 



By Leonard Hill, M.B., F.E.S., D. Hargood-Ash, B.Sc, and J. Argyll 



Campbell, M.D. 



(Received January 7, 1922.) 

 (From the National Institute for Medical Research, Hampstead.) 



The object of this enquiry is to find out how much heat can be gained, or 

 cold lost from the body, by the local cooling or warming of a small part, e.g., 

 by cooling the hands in a stream of cold water, warming the feet in a hot foot- 

 bath, or by a foot-warmer. In order to secure the beneficial effect of open 

 windows, the breathing of cool air of low-vapour tension, and stimulation of 

 body metabolism by such air ventilating the clothed and naked parts of the 

 skin, the general heating of rooms by hot-water coils might be replaced by 

 small heaters kept a few degrees above body temperature and locally applied 

 to each individual, and each under the individual's control. Electric heaters 

 have been used by aeroplanists placed beneath their outer garments. 



One of us(l) recently published results showing that heating or cooling the 

 hands can effectively heat or cool the whole body. We record further experi- 

 ments of a like nature. 



In some of these experiments, in which the hands were placed in cold 

 water, we estimated the respiratory exchange by the Douglas-Haldane method 

 of indirect calorimetry. We obtained in paost cases a small rise in body 

 .metabolism after immersion of both hands in cold water at 15° C. for about 

 30 minutes. The rise in metabolism was too small to be termed definite. 

 The amount of heat lost from the hands to the water was evidently replaced 

 by cutting down heat lost from other parts of the body. The actual amount 

 of heat lost from the two hands in 30 minutes was, on an average, 20 kilo- 

 calories. A greater loss of heat is therefore necessary before metabolism is 

 affected. 



The temperature of the skin over the median vein at its bifurcation on the 

 front of the elbow was recorded by means of a flat-coiled thermometer insulated 

 from the air. The temperature of this portion of skin fell several degrees in 

 the above experiments. 



Macleod (2) and others have applied heat and cold to the surface of the 

 shaved body of rabbits to study the changes of temperature in underlying 

 tissues and in various organs — muscle, liver, kidney and brain. They used 

 thermo-electric couples mounted in hypodermic needles. They showed that 



