ebb cold baths may be weakening if prolonged beyond a few seconds. For one with skin relaxed and body sluggish from indoor life, cool baths arouse activity, tone up the body, and may be as beneficial as outdoor exercise in restoring vigorous health. As with every hygienic measure, each person must find out by experience what suits him best.
Clothing was first employed for ornament. In cold climates it aids
in maintaining the uniform temperature of the body; to it man owes
his distinction of being the most widely distributed of animal species.
Clothing prevents rapid escape of bodily heat by confining air, a non-*conductor
of heat, in its meshes. Hence, the effect of clothing varies
with the weave; likewise with the tendency of its fibers to keep dry, for
if water replaces air in the meshes, the body loses heat rapidly. For
cool clothing the weave should be hard and tight, for warm clothing it
should be soft and loose. The warmth of clothing is affected more by
its weave than by its weight. The weave may be tested by stretching;
the fabric with softest weave will stretch the most (Exp. 8). Linen
makes the coolest of all clothing because it weaves hard with small
meshes; silk ranks next in coolness. When warmth is desired, linen
or cotton garments should be made of fabrics woven like stockings.
Linen and cotton both absorb water rapidly and dry rapidly (Exp. 6);
if woolen did also, it would make the warmest of all clothing, but it
dries so slowly (Exp. 7) that it cools the body after the activity is over
instead of drying rapidly and, as with linen and cotton, keeping the
body cool during the exertion (Exp. o). Woolen weaves with the
largest air meshes of all materials; hence its warmth increases perspiration,
but woolen removes perspiration most slowly and tends to relax
the skin if the wearer has an active skin or makes active exertion.
Woolen is best for underclothing during extreme cold only or for persons
who never make such vigorous muscular exertion as to perspire.
In general, cotton or linen is best for underwear. They possess the
added advantages of less cost and of not shrinking out of size and
shape when washed. A mixture of cotton and silk or of cotton and
wool is more durable than either alone. Cotton and linen, unlike
woolen, are not attacked by insect pests.
It is better to depend more upon outer clothing than underclothing for warmth. In the Gulf states the wearing of woolen outer clothing indoors during warm weather (which lasts eight months) is unhealthful and uncleanly because of the perspiration absorbed; this is as
