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Practical Hydrotherapy

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Seventh-day Adventist Publishing Association · Battle Creek, Mich. · Mar 18, 1902

FromReview and Herald, Vol. 79, No. 11.

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Practical Hydrotherapy

By GEO. THOMASON, M. D.

Lesson 5 — General Effects of Heat and Cold

GEO. THOMASON, M. D.
(Concluded from last week)
Heat may be applied to the body in a variety of ways; for example, by means of hot water, as the full immersion bath, the spray, by the application of flannels wrung from hot water, or by vapor, as in the Russian bath. As mentioned in the previous article, in hydriatic treatment, actual steam is never allowed to come directly in contact with the tissues.
Another method of communicating heat to the body is by means of the Turkish, or hot-air, bath. Again, by means of a cabinet arranged with incandescent electric lights, heating of the superficial structures of the body may be effected by exposure of the body to the direct rays from the lamps. The effect of this bath is quite analogous to that of sunlight.
The effect of heating procedures depends upon the manner in which the application is made; namely, whether as a passive application, such as the immersion bath, or accompanied by percussion, as in the douche. The temperature is also of great importance, as mentioned in the previous article, all temperatures above 90° being recognized as hot.
The length of the time during which the application of heat is made to the body also determines the result produced. The duration of the application must be diminished the higher the temperature used. A neutral bath, namely, at a temperature of from 62° to 95°, may be continued indefinitely. A full bath at a temperature of 110° cannot be tolerated by the ordinary patient for more than from five to eight minutes. A full bath at from 115° to 120° would be extremely hazardous if continued for more than one or two minutes. Local applications, of course, may be tolerated at higher temperatures than general applications, and for a much greater length of time; as, for example, the immersion of the feet or hands in hot water, or hot water drinking, or the enema.
The usual temperature of the vapor, or Russian bath, is from 115° to 120°, or it may be increased to 130° or even 145° for a brief period. Hot dry air, as in the Turkish bath, can be tolerated at a much higher temperature, but the temperature usually employed is from 140° to 180°. Temperatures from 225° to 250° are not uncommonly employed, and persons accustomed to taking these baths, or in the habit of subjecting their bodies to high temperatures, may endure a temperature as high as 400° or 450°. Cases are on record in which persons have exposed their bodies to heat in an apartment raised to a temperature sufficient to bake bread, and have remained during the entire time the bread was in process of baking. It is necessary that the air under such circumstances should be absolutely dry.
The effect of heat is to promote cell activity. Thus it favors the process of growth and development. The sun is, of course, the original source of heat, and sunlight favors the growth of animal and vegetable life. When moderate heat in any form is applied to the skin, it excites the activity of the circulation, producing a reddening of the skin, and if continued, will excite the activity of the perspiratory glands. The increase of circulatory and perspiratory activity as the result of the hot application increases the elimination of heat from the body, which is nature's method of protecting the body from too great an accumulation of heat within the body, which would otherwise result from the hot application.
The evaporation of moisture from the skin is the principal means by which the body is cooled. This evaporation from the skin is constantly taking place, varying according to the season of the year, and the conditions to which the body is subjected. In the winter, when it is desirable to conserve the heat of the body, the skin is comparatively dry, and the extra clothing worn at this season also greatly lessens the rate of evaporation. In the summer, when it is necessary for the body to eliminate heat rapidly, the amount of perspiration is greatly increased, and rapid cooling of the body occurs by means of evaporation of the moisture. A dry atmosphere facilitates evaporation, hence lessens the tendency to the accumulation of heat within the body, and consequent sunstroke. When the humidity is great, or the air well saturated with moisture, evaporation of the perspiration occurs with much less facility, and there is a feeling of oppression; the heat becomes less endurable, and the tendency to sunstroke is greatly increased.
General applications of heat increase the rate of the heart-beat. Normally, the heart beats seventy-two times a minute. By the application of heat to the body the heart-beat may easily be increased to double the normal rate. The increased heart-beat is the result of an effort on the part of nature to keep as much blood as possible in the skin, to increase perspiratory activity, and thus to increase the elimination of heat from the body. As soon as free perspiration occurs, the activity of the heart is diminished.
A prolonged general application of heat greatly lessens muscular activity. This is readily apparent if a full hot bath be taken for ten or fifteen minutes. A patient may feel so much exhausted and weakened by the hot bath as to be scarcely able to walk or stand upon the feet. A person in such condition, however, is quickly revived by a short cold spray, or other form of cold application. When the muscles are exhausted as the result of great muscular exertion, a short application of heat restores the muscular tone, and if followed by a short application of cold, produces a remarkable restorative effect under such conditions.
It is well to bear in mind the relaxing effect of heat upon the muscular and fibrous structures of the body. In case of fracture or dislocation of a limb, the time intervening between the accident and the arrival of the physician may be spent very profitably in vigorous applications of heat to the affected part. The immersion of the part in very hot water, or the application of large fomentations, will greatly diminish or entirely relieve the pain, and will also so relax the surrounding structures that the fibrous tension and muscular rigidity will be greatly lessened, and the setting of the fracture or reduction of the dislocation much facilitated.
The relaxing effect of heat often renders great service in cases of strangulated, or so-called irreducible, hernia, in which a portion of intestine has escaped through an opening in the tissues and cannot be replaced. The application of large very hot fomentations for a half-hour or an hour, or the immersion of the affected part in as hot water as can be tolerated, will frequently so relax the tissue which incarcerates the intestine that it may be pushed back into place by pressure with the hand, and thus obviate the necessity for a severe surgical operation.
It is necessary to bear in mind that heat, as well as cold, has a primary and a secondary, or an action and a reaction, effect. The first, or primary, effect of heat is to excite and stimulate cell activity, but the secondary, or reaction, effect is sedative or depressing in its effect. This effect is the same upon the heart, nerves, blood vessels, muscles, and other tissues. For example, when an application of heat is made to the skin, it produces reddening of the skin, due to the opening up of its blood vessels, and an increase in perspiratory activity. Upon withdrawal of the application, the secondary, or reaction, effect becomes apparent, and there is a pallor of the skin, due to the contraction of the blood vessels, and a diminished or suspended perspiratory activity.
Bearing in mind the principles in reference to hot and cold applications, it is possible, by a combination of these applications, to produce any desired effect. For example, if it is desired to produce a lasting exciting or tonic effect, we may first make an application of heat, utilizing its first, or primary, effect, which is exciting, and immediately follow this by a short cold application, the secondary, or reaction, effect of which is also stimulating or exciting, and which effect remains permanent.

QUESTIONS

1. Name the principal ways in which heat is applied to the body.
2. On what three things does the ultimate effect of the hot application depend?
3. What temperatures may be used in the various forms of hot applications?
4. What is the source of all heat? and what effect does heat have on cell activity?
5. What is the principal means by which the body is cooled?
6. What is the general primary and secondary effect of heat?
7. Give two illustrations of the practical use of the relaxing effect of heat upon the tissues.