=Temperature of the Body.=--By a wonderful provision of nature, the temperature of the surface of the body is preserved at about 98.4 degrees Fahrenheit, whether the individual resides in the arctic regions or within the limits of the torrid zone. The range of the internal heat of the body is not very great. A deviation of seven degrees from the normal is dangerous. If the temperature of the body rises to 109 degrees or falls to 76, death is almost sure to follow.
=Temperature and Kinds of Baths.=--From the standpoint of temperature, baths may be classed as hot, warm, tepid, cool, and cold. A hot bath has a temperature ranging from 98 degrees to 112 degrees Fahrenheit; a warm bath from 92 degrees to 98 degrees; a tepid, from 85 degrees to 92 degrees; a cool bath from 60 degrees to 75 degrees; and a cold bath from 60 degrees down to the freezing point of water.
Tepid, warm, and hot baths are employed, not only for cleansing the body, but to diminish blood pressure and to reduce nervous excitability. The hot bath is used in restoring warmth to the body in certain cases of shock, and to remove the effects of exposure to a low temperature.
When the water is of about the same temperature as the body, the effects are neither stimulating nor depressing. In some forms of sleeplessness, a tepid bath taken just before retiring has been found to be effective. In such cases, the body should be covered by the water for ten or fifteen minutes, and quietly dried with a soft towel, without vigorous rubbing or friction.
=Hot Bath.=--The cold bath stimulates, the hot bath facilitates function. Both hot and cold baths increase the combustion going on within the body. The immediate effect of a cold bath is to chill the surface of the body. This sensation is promptly conveyed by the nerves of the skin, through the spinal cord, to the brain. Respiration and circulation are at once increased, and the temperature of the interior of the body is raised.
The effect of a hot bath is to raise the temperature of the surface of the body and the temperature of the blood. As in the case of a cold bath, the respiration and pulse are quickened, and the escape of carbonic acid from the lungs is increased.
