503 general therapeutic measures 



Heat. 



Water at a moderate degree of heat — ^hat is termed lukewarm — 

 i. e., 86° to 95° F., applied to the body, stimulates the action of the 

 skin, relaxes peripheral vessels and diminishes nervous excitability^ pain 

 and spasm in neighboring parts. Water at a temperature of 112° to 

 120° F. contracts blood vessels of underlying parts, relieving congestion 

 and pain. Such a degree of heat resembles cold in its effect, and they 

 may often be used interchangeably. Still stronger heat has much the 

 same effect as excessive cold, only acting more quickly, causing dilatation 

 of the vessels, pain, inflammation and destruction of tissue. The action 

 of povrerful heat on the whole body, or upon single organs is similar to 

 that of counter-irritants. Mild, moist heat is beneficial in the treatment 

 of wounds in poorly vascular parts where there is a tendency to indolent 

 granulation, as about the feet in horses. Again, in low grades of inflam- 

 mation with induration, as in strains of tendons, where moderate heat 

 tends to stimulate the circulation and hasten absorption. In the treat- 

 ment of abscess and burns, with destruction of tissue and suppuration, 

 moist heat applied locally macerates the dead tissue, hastens sloughing 

 and relieves pain, and in softening parts prevents the burrowing of pus 

 and the formation of deep-seated pockets and sinuses. 



A modern view of poulticing is that it -aids the migration of leuko- 

 cytes, and therefore is productive of good in assisting their phagocytic 

 action. Hot applications increase exudation, congestion, collection of 

 leukocytes and opsinins, locally. All these results are inimical to bac- 

 terial growth. The abscess can thus be more speedily formed and more 

 quickly defined. Herein heat differs from cold. In irritable and spas- 

 modic troubles of muscular origin in various organs, heat is distinctly 

 remedial, as in pelvic and abdominal pain and colic, when employed in 

 the form of rectal injections. Heat may, in many conditions, be used 

 interchangeably with, or in the place of, cold, according to the preference 

 of the practitioner or the effect upon the patient. As, for instance, in 

 the case of pneumonia, pleuritis, angina, and in checking hemorrhage. 

 Heat may be utilized in simply preventing the natural radiation of it 

 from the body.- Thus, simple, warm, dry blankets, applied all over the 

 surface of the body, may abort catarrhal or rheumatic conditions by 

 merely causing retention of the body heat, dilatation of the peripheral 

 vessels and equalization of the circulation. Covering a portion of the 

 skin with such dense preparations as tar, pitch or collodion, in mild 

 superficial inflammatory lesions, is said to produce favorable results by 

 restraining radiation and increasing heat and blood supply in the part. 

 Even thickened tendons and indurated glands may be benefited thereby. 

 The Priessnitz poultice continuously applied has a similar action. In 

 vasomotor paralysis, seen in collapse, following loss of blood or poisoning, 

 and in shock due to traumatism or surgical operation, heat is eminently a 

 life-saving means. In such conditions the loss of vascular tone and 

 dilatation of the vessels lead to dangerous, and even fatal, cooling of the 

 body. Heated dry blankets, or those wrung out in hot water, should be 

 applied to the larger animals, together with hot rectal injections; while 



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