ns not only predispose to colds, but increase their severity and
the danger of complicating infection of the bony cavities in the skull
that communicate with the nose. They also increase the liability to
involvement of the middle ear and of the mastoid cells which are located
in the skull just behind the ear. The importance, therefore, of having
the nose and throat carefully examined, and of having any diseased
condition of the mucous membrane or any obstruction corrected must be
apparent. All who suffer from recurrent colds should take this
precaution before winter sets in.

[Sidenote: General Resistance]

If the nasal passages are put in a healthy condition, strict obedience
to the rules of individual hygiene will almost wholly prevent colds. In
fact, except where actual nasal defects exist, the frequency of colds is
usually a fair indication of how hygienically a person is living. The
following points need especial emphasis, though they repeat in some
cases what has already been said in the text.

[Sidenote: Skin Training]

It is a familiar fact that exposure and chilling will often produce a
cold. This is usually due to the fact that the nerve centers
controlling the circulation of the skin are over-sensitive, and exhibit
a sort of hair-trigger reaction to exposure, causing a disturbance of
the circulation, and of the heat-regulating machinery of the body of
which the spongy shelf-like turbinated bones in the nose are an
important part. Skin training, then, appears to be the first hygienic
steps toward establishing a resistance to colds.

Such training for the skin may be secured by various means. One should
first accustom himself to a gentle draft.

Cool bathing, to a point that produces a healthy reaction, is another
important feature of skin training.

Cold bathing, by those affected with kidney trouble, is not advisable,
but delicate individuals, who cannot react well to the cold bath, can
greatly increase their resistance by graduated cool bathing performed as
follows: Standing in about a foot of hot water, one may rub the body
briskly with a wash cloth wrung out of water at about 80 degrees F. and
reduced day by day until it is down to 50 degrees F. Following this the
cold douche or affusion may be taken (water quickly dashed from a
pitcher) beginning at 90 degrees F. and daily reducing until
50 degrees F. is reached, or just before the point where an agreeable
reaction ceases to follow.

[Sidenote: