x 76 Journal of Agricultural Research voi. ix, No. 6 
to an apparent relationship between the body temperature of man and 
the temperature of his environment, even under ordinary conditions of 
living. It was found, for example, that during summer months the 
rectal temperature at 8 a. m. of people living in their own homes was 
conditioned by the average atmospheric temperature of the preceding 
night. If the temperature had been warm, the body temperature in 
the morning was high; if cool, the body temperature was low. The 
variation was about i° F. for 20 degrees of atmospheric temperature. 
The body temperature was lowered by confinement in an atmosphere 
of 68° and 50 per cent relative humidity and raised by confinement at 
75 0 with the same humidity, or still more by 86° with 80 per cent hu¬ 
midity. The actual body temperatures found at these stages, respec¬ 
tively, were 98°, 98.5°, and 99.3 0 . 
In extreme atmospheric conditions greater elevations of temperature 
are known to occur (1). A stay of about three hours in an atmosphere 
averaging 104.7 0 in temperature and 95 per cent relative humidity may 
produce a rise of several degrees in the body temperature of a normal 
adult man. 
Schroeder and Mohler (8), in their bulletin dealing with the tuberculin 
test of hogs, state that, when the temperature of a number of hogs is 
compared, the difference found is of such magnitude that they are at a 
loss to conclude what should be regarded as normal. Other than stating 
that the normal variations that occur in individual hogs are very great, 
they do not give any figures. These workers have also found that fat 
hogs have a higher temperature than lean ones and that a higher tem¬ 
perature induced by exercise or some other temporary cause persists 
longer in fat than in lean hogs. 
We have not collected any large amount of data concerning tempera¬ 
ture variations in normal pigs other than the temperature records which 
accompanied our blood experiments. These experiments, however, 
very clearly demonstrated the extreme variability in the temperature of 
pigs. 
Merely being in the direct rays of the sun will cause a marked increase 
in the body temperature, the increase, of course, varying with the 
atmospheric temperature and relative humidity. On a hot day a normal 
pig exposed to the direct rays of the sun may show a temperature as high 
as 106 0 to 108 0 F. 
The handling of or working among a group of pigs for only a few minutes 
can cause a marked increase in their body temperatures. For example, 
a black sow weighing 102 pounds had been quiet in a small pen for two 
days. Her rectal temperature was then 102.8°. She was then picked 
up and placed in a hog crate, the operation requiring only a few minutes, 
but it caused a rise in the rectal temperature to 104°. 
A black sow weighing 130 pounds and in good condition, but not? fat, 
had been confined for several days in a small pen. Before taking her out 
