There is no physical agent which exerts a more constant or more powerful
influence upon health and life, than the atmosphere. The climate in
these latitudes is exceedingly variable, ranging all the way from 110°
Fahr. in summer to 40° below zero in the winter season. The body of
every individual should be so protected from cold, that it can maintain
a mean temperature of 98° Fahr.

When the body is warm there is a free and equal circulation of the blood
throughout all the structures. When the surface is subjected to cold,
the numerous capillaries and minute vessels carrying the blood, contract
and diminish in size, increasing the amount of this fluid in the
internal organs, thus causing congestion. The blood must go somewhere,
and if driven from the surface, it retreats to the cavities within.
Hence this repletion of the vital organs causes pain from pressure and
fullness of the distended blood-vessels, and the organic functions are
embarrassed. Besides, cold upon the surface shuts up the pores of the
skin, which are among the most active and important excretory ducts of
the system. It is evident, then, that we require suitable clothing, not
only for comfort, but to maintain the temperature and functions
essential to health and life.

The chief object to be attained by dress is the maintenance of a uniform
temperature of the body. To attain this end, it is necessary that the
exhalations of the system, which are continually escaping through the
pores of the skin, should be absorbed or conducted away from the person.
These exudations occur in the form of sensible or insensible
perspiration, and the clothing, to be healthy, should be so porous as to
allow them freely to escape into the air.