Use of Water, Heat, and Light. Heat, cold, water and light are effective because of their action upon the distribution of circulation, rate of metabolism, the local and reflex nerves, the heart action, the chemical condition of the blood. Their therapeutic use has only in recent years become a science. Extensive study and experience is necessary for their efficient application. A few fundamental principles will guide in their ordinary use, but only a physician trained in hydrotherapy and thermotherapy can give directions meeting every factor in an individual case.
Applications affect not only the local part but also the parts with which it is reflexly connected. The volume of blood can be withdrawn from any part or to any part. The first effect of hot applications is stimulating; continued for more than ten or fifteen minutes (after the surface is reddened) is depressing. Cold is first depressing; continued slightly is stimulating, and long continued becomes depressing. Alternate heat and cold for three to ten minutes is the most stimulating.
Pain, inflammation or increased secretion in any part usually indicates local congestion of blood which needs to be withdrawn. Congestion in the head, indicated by headache or cold; or in the chest, indicated by chest cold; or in the abdomen or pelvic organs, can be reduced either by a general distribution of blood to the surface or by withdrawing the supply to the legs and feet. A hot bath or pack draws the supply to the surface; a hot leg bath or pack draws it to these extremities. The cool sponge following the hot water keeps the blood in these parts, besides reducing the temperature of the superheated surface and toning up the skin. Hot fomentations draw the circulation to the surface, away from the congested internal parts directly beneath or reflexly connected. Thus, heat applied to the forehead and base of brain reduces head congestion; or as fever is usually present, cold (50° F.) will have the same effect and at the same time reduce the temperature, while a hot-water bag at the feet will maintain the temperature if the fever is mild or absent. Congestion in the abdomen or pelvic organs is relieved by local applications of heat to these parts and to their reflex areas—the buttocks, thighs, feet and hands.
In using heat or cold, the application must be changed whenever its temperature approaches that of the body. Local hot applications may be continued until the surface is reddened—from five to twenty minutes. The surface is then sponged quickly with water, or 25% alcohol, at 70°-80° F., to prevent superheating of tissues. Cold general sponging in fever may be continued ten or fifteen minutes, one part sponged and dried at a time, patient covered with a light blanket; and repeated every hour. Local cold, as icebags or cold cloths, may be continued half an hour, and repeated at half hourly intervals. A cold compress is a mild counter-irritant. Water reaches tissues below the surface, and for deep-seated disorders is therefore more effective than dry applications, when practicable. Care must be taken to protect hair, clothing and bedding from dampness, by use of rubber cloth or oiled silk. For young children, temperatures must be less severe and changes more gradual than with adults. The nurse should test the heat of applications by applying to her own face.
Hot Tub Bath. For chills, convulsions, incipient cold, general depression without fever. If patient is constipated or had no movement in preceding twelve hours, precede by enema, as hot water increases absorption from intestinal tract. Give in warm room (70° F.), at 100° F., or higher for children over four years. One tablespoon mustard (in cheesecloth bag) per gallon of water increases effect. Wrap cold cloth around neck, and protect hair. Continue five to ten minutes, until skin is red, adding hot water carefully to slightly raise temperature. Give quick hand rub with water at 80° F. unless sweating is desired. Dry quickly, wrap and cover warmly. Giving water to drink will increase perspiration. After perspiring, rub with 25% alcohol.
Hot Leg Bath. For intestinal pain, headache, incipient cold, cold feet, convulsions. Conditions and temperatures as for tub bath. Keep patient well covered. Can be given with patient lying in bed, water in bucket on chair at side of bed. Rinse with lukewarm water, put on stockings, and keep hot-water bag at feet.
Hot Fomentations. To relieve local pain and congestion. Apply one or two thicknesses of flannel to place; lay on this a double flannel wrung out of boiling water, and cover with dry flannel and waterproof. Be careful that it is not too hot at first. In changing, prevent air striking part. Change every three minutes, and continue twelve minutes. Sponge quickly with water 70°-80° F.
Warm Tub Bath (90°-93° F.). For nervousness and irritability. May continue, maintaining temperature, for half an hour.
Dry Heat. For chills, neuralgia, rheumatic pain, earache. Use thermophore, hot-water bottle, hot flannel, salt, bran, hops, soapstone, flatiron wrapped in flannel, or Japanese handstove. In using hot-water bag, be careful it is not too hot; wrap in flannel, and watch for leakage. Water should be below boiling or rubber will be damaged. Press out air before putting in stopper. Remove when cool. If electric pad is used, turn off current when hot. Continue dry heat for half hour periods; sponge quickly with water 80° F.; repeat at half hour intervals if necessary.
Light. Light rays penetrate about two inches below the surface, and therefore continue the therapeutic effects of heat to the deeper tissues. Systematic sun baths may be given. Carbon electric light gives the same effect; it cannot be used to advantage, however, with children under four or five years. For pain in chest, sore throat, abdominal pain, may be used instead of hot water or dry heat. Concentrate the light and protect the skin from contact with bulb by a cone made of white paper. For earache, use the smallest size bulb. Apply for fifteen or twenty minutes, until redness is induced, then give quick cool sponge. May be repeated several times during day.