ring. It should not be necessary to
bury one's self underneath a heavy load of covers in order to keep the
feet warm. Use as little covering as possible and still maintain the
bodily warmth. Eider-down bed covers are very valuable because of
their light weight and great warmth-retaining qualities. Overheating
during sleep produces restlessness and robs one of the sense of
refreshment on awakening. The question of cold feet I have already
dealt with. The difficulty, in most cases, is one of defective
circulation before going to bed. If one will be sure that his feet are
warm and his circulation good before retiring to bed he will invariably
have no trouble of this kind, even during winter time. I do not mean
that one should be chilled by insufficient bedding, but I certainly
would advise as little covering as is compatible with a comfortable
degree of warmth.

The feather beds, much used in Europe, are undesirable, as they are
unsanitary and are too warm for nearly all seasons of the year. It is
always best to sleep between clean linen sheets. For purposes of warmth,
however, bear in mind that cotton is of very little value, whereas
animal-product covers such as wool and down, or feathers, are
exceptionally warm. Cotton comforters in cold weather are very heavy,
but cold, whereas woolen blankets, wool-filled comforters or down-
filled comforters are warm, but light. "A warmth without weight" should
be the chief consideration in cold weather. And in using woolen
coverings you can get sufficient warmth without much weight and with the
very least quantity of covering. In summer use only a single woolen
blanket or a light cotton coverlet over the sheet. When the nights are
hot and sultry it would be well to use no covering of any kind.

For warmth in winter special attention should be given to warm fabrics
underneath the lower sheet as well as the coverings. One may
become chilled from underneath if lying upon a thin mattress or an
uncovered mattress. A wool-filled comforter, or double woolen blanket,
placed over the mattress and under the sheet will contribute greatly to
one's warmth. If the mattress is of proper thickness one can be
comfortable with less covering and therefore less weight. However, I
would suggest as a better plan the one that I have presented of sleeping
in a virtual air bath the whole night through.

The use of a pillow is necessary in nearly all cases. When one is