PHYSICAL BIOCLIMATOLOGY 
face conductance of the passing air ha, and the effective 
surface area of the membranes /’. Then the heat trans- 
ferred to the inhaled air during its passage into the 
lungs is given by 
hal’ (Js — Ji) = Mpcp(Jy — Ji), (18) 
and the total heat loss of the body by respiration, 
A = Moc,J. — Ji) = had, — Js), (19) 
in which gq is a relative time factor depending on the 
40 
SKIN TEMPERATURE 
© G.NEUROTH .........-.. 
+ BUETTNER AND KONIG... 
1117 
0.75 (mouth) and from 0.84 to 0.62 (nose) if J; changes 
from 100C to —40C. The slight dependency of P on 
M may be explained by a compensatory effect of MZ 
and F (cooling of deeper tracts with a deep breath). 
When the inhaled air is very warm and dry, the exhaled 
air is no longer saturated [11]. In any case, J, is by no 
means constant but decreases with J;. 
At higher altitudes, A becomes an important part 
of the total heat loss: If 7 increases to compensate for 
the decreased partial pressure of O2 (Mp = M'p’), 
then the “dry” loss M’p'(# — &;) remains the sam'z 
++ sans CHAMBER 
CHAMBER 
X BUETTNER AND FRANK.....ZUGSPITZE + 
—— PFLEIDERER, KAYSER, “et Te 
sate -OUTDOORS 4" O# 
AND BUETTNER. 
MEAN SKIN TEMPERATURE (°C) 
+10 
INCREASED O05 CONSUMPTION (%) 
+20 +30 
EFFECTIVE TEMPERATURE (°C) 
Fie. 1—Mean skin temperature of supine, nude persons at rest, in terms of ‘effective temperature.”’ Data are partly from. 
a climatic chamber and partly from various climates in the open air (North Sea coast, Alps, central Africa). The abscissa 
has been converted to ‘‘effective temperature’ on the basis of original values (temperature and humidity) according to the 
method of the A.S.H.V.E. for unclothed persons. In the case of cool and windy conditions, which prevailed for the most 
part at “‘effective temperatures” below 20C, the ‘‘temperature of equal effectivity” [18, 19] was used instead of the ordinary 
air temperature. Only in the central range were climatic conditions such that they could be withstood for several hours. 
The duration of experiments in the two extremes was about 14 hr. The metabolism curves (after Wezler [83]) in the lower 
right show the heat production measured by oxygen consumption of supine, nude persons as a function of “‘effective tem- 
perature.’’ Data were obtained from four persons in a climatic chamber and show noticeable differences at the lower tem- 
peratures. 
rhythm and relative length of the breath pause; hence 
ake = dis ¢ 
ay Pth., q, M, ha, F). (20) 
This calculation may be considered as a first attempt 
to find a connection between the observed temperatures 
without knowing J;. 
A comprehensive study of all available measurements 
for the case of normal mouth or nose breathing (not 
yet published; see [11, 17, 19, 70]) reveals a drop of J, 
from 125C (mouth) and 125C (ose) down to 82C 
(mouth) and 65C (nose), respectively, if J; changes 
from 100C to —40C. The average M = 0.6 m® hr~* 
in these experiments. The variation of the function P 
with J; is remarkably small: it drops from 0.84 to 
(observations in a pressure chamber have yielded the 
same values of temperature and saturation as at sea 
level). However, the ‘‘wet” portion M’C(H. — e;) 
increases with M’/M. (C includes the heat of vaporiza- 
tion and the conversion from e to absolute humidity.) 
Exercise, fever, etc., have little influence on the relative 
amount of heat loss by breathing because increased 
internal combustion requires a higher JM. 
Tn general, the heat transfer due to breathing may be 
considered as small compared to the transfer through 
the skin. 
The General Effects of Climate. Let us consider on 
the basis of our formulas how the body stabilizes its 
temperature, that is, how it balances its gain and loss 
of heat. In the ‘‘comfort” range, Q is at a minimum, 
8, is about 33-34C, and f = 0. If &% or é rises, Q at 
