Silk ranks next to wool in warmth and porosity.  It is much softer and less irritating than flannel or merino, and is very useful for summer wear.  The practical objection to its general use is the expense.  Fur ranks with wool as a bad conductor of heat.  It does not, however, like wool, allow of free evaporation.  Its use in cold countries is universal, but in milder climates it is not much worn.

Cotton and linen are good conductors of heat, but are not absorbents of moisture, and should not be worn next the skin.  They are, however, very durable and easily cleansed.  As an intermediate clothing they may be worn at all seasons, especially over wool or silk.  Waterproof clothing is also useful as a protection, but should not be worn a longer time than necessary, as it shuts in the perspiration, and causes a sense of great heat and discomfort.

The color of clothing is of some importance, especially if exposed directly to the sun’s rays.  The best reflectors, such as white and light gray clothing, absorb comparatively little heat and are the coolest, while black or dark-colored materials, being poor reflectors and good absorbents, become very warm.

251.  Suggestions for the Use of Clothing.  Prudence and good sense should guide us in the spring, in changing winter flannels or clothing for fabrics of lighter weight.  With the fickle climate in most sections of this country, there are great risks of severe colds, pneumonia, and other pulmonary diseases from carelessness or neglect in this matter.  A change from heavy to lighter clothing should be made first in the outer garments, the underclothing being changed very cautiously.

The two essentials of healthful clothing are cleanliness and dryness.  To wear garments that are daily being soiled by perspiration and other cutaneous excretions, is a most uncleanly and unhealthful practice.  Clothing, especially woolen underclothing, should be frequently changed.  One of the objections to the use of this clothing is that it does not show soiling to the same extent as do cotton and linen.

Infectious and contagious diseases may be conveyed by the clothing.  Hence, special care must be taken that all clothing in contact with sick people is burned or properly disinfected.  Children especially are susceptible to scarlet fever, diphtheria, and measles, and the greatest care must be exercised to prevent their exposure to infection through the clothing.

We should never sleep in a damp bed, or between damp sheets.  The vital powers are enfeebled during sleep, and there is always risk of pneumonia or rheumatism.  The practice of sitting with wet feet and damp clothing is highly injurious to health.  The surface of the body thus chilled may be small, yet there is a grave risk of serious, if not of fatal, disease.  No harm may be done, even with clothing wet with water or damp with perspiration, so long as exercise is maintained, but the failure or inability to change into dry garments as soon as the body is at rest is fraught with danger.