PHYSIOLOGY: BENEDICT, MILES AND JOHNSON 219 
a light tuft of cotton batting and installed rigidly in a piece of hard rubber, it 
was possible to apply it to the body and have it assume the surface tempera- 
ture inside of a few seconds. Thus the period of apphcation was so short that 
the protecting m.aterial did not sensibly affect radiation, conduction, or the 
vaporization of water. 
In our ordinary skin temperature measurem.ents, the junction in the con- 
stant temperature bath is kept at 31° or 32°C. When the other junction is 
exposed to usual room temperature, there is a large deflection of the galva- 
nometer. On applying the junction to the surface of the skin, the amplitude 
of deflection decreases rapidly and with negative acceleration. The deflection 
level is reached in about six seconds after apphcation of the junction. There- 
after the rate of movement of the galvanometer is extremely slow, being but 
a millimeter or two for each successive minute. The explanation of this is 
that the junction almost instantly assumes the true skin temperature. There- 
after the skin temperature gradually rises, as the protection of the junction 
with cotton batting and hard rubber stops the loss of heat by radiation, 
conduction, and vaporization of water, and there is then a 'building up' of the 
temperature due to the subcutaneous source of heat. As a matter of fact, ob- 
servations taken for some time show that this rising temperature continues, 
the length of time depending in large part upon the amount of hard rubber 
and cotton batting used. For all of our work we have assumed that under 
these conditions the true skin temperature is obtained at the end of about six 
seconds after application of the junction. 
In connection with an extended series of metabohsm experiments on the in- 
fluence of temperature environment upon the metabolism, it was found that the 
subject used (a professional artist's model) could withstand exposure to tem- 
peratures as ]ow as 14°C. for several hours without shivering. These condi- 
tions presented unusual opportunities for studies of skin temperature which 
would give evidence first, as to the rapidity of the change on exposure of the 
body to the environmental temperature, and finally as to the absolute level 
which the skin temperature reaches after prolonged exposure to an environment 
varying from 14° to approximately 30°C. 
When the subject arrived at the Laboratory, the clothing was loosened and 
temperature measurements were made at numerous points on the skin under 
the clothing. Prior to these records, the subject clothed and wearing a heavy 
coat had been exposed to an external temperature of about 17°C. The results 
of one series of measurements are recorded in table 1. The extreme range in 
the skin temperature on this particular day was6.6°C. Special attention is 
called to the relatively high value of 31.6°C. on the exposed forehead, the rec- 
ord of approximately 34°C. at the waist, a part well protected by clothing, 
and values of 30°C. or below on the buttocks, shin, and calf. This series is 
tj^ical of the skin temperature of a normally-clothed woman. 
