Heat-Stroke.

Synonyms.—Sunstroke; Coup de Soleil; Insolatio; Febris Solarie, or Sun Fever; Thermic Fever.

Definition.—Heat-stroke is the result of exposure to intense heat, either from the direct rays of the sun, or the radiation of blasts or furnaces, or to an overheated atmosphere.

Etiology.—Among the predisposing causes may be mentioned intemperance in drinking spirituous or malt liquors, physical or mental exhaustion, or anything that impairs the vital force or the resisting power of the body. A moist atmosphere, owing to interference with evaporation and the consequent cooling of the body, favors heat-stroke.

The immediate cause is always exposure to heat, either natural or artificial, and this excessive heat, acting upon the "heat center or vasomotor center or nerves," produces thermic fever, or heat exhaustion.

Lambert and Van Gieson hold to the theory that sunstroke is due to auto-intoxication, heat being only a contributing cause. Sunstroke occurs most frequently among bricklayers, roofers, masons, hod-carriers, teamsters, and soldiers upon hard marches, especially if they are beer-drinkers.

Heat-stroke occurs most frequently among stokers, workers in foundries, glassworks, boiler-rooms, laundries, and in all cases where the heat is confined.

Pathology.—Owing to the excessive heat of the body, putrefactive changes occur very early. If a post-mortem examination is made soon after death, the left heart will be found contracted, while the right heart will be engorged, and the venous trunks filled with dark semi-fluid blood. There is also venous engorgement of the brain, spinal cord, and lungs, and sometimes degeneration of the spleen and kidneys.

Granular degeneration of the ganglion cells of the brain and spinal cord has been observed.

Echymoses and extravasations of blood are found in the skin and mucous membranes, and also around the cervical sympathetic ganglia, the vagus, and phrenic nerves. The blood-corpuscles are crenated and show a diminished tendency to the formation of rouleaux.

Symptoms.—There may be prodromal symptoms, such as dizziness, intense burning headache, chromatopsia or colored vision, and a hot, dry skin. Usually, however, the attack comes on suddenly, and the patient loses consciousness. The breathing is stertorous, or shallow and rapid, the respiration varying from thirty to fifty per minute. The face is flushed or cyanotic, there is throbbing of the carotids, and the pulse is rapid, from 130 to i6o beats per minute. The temperature for mouth or rectum is rarely less than 108°, and may reach 113° or 115°. The skin is hot and dry, though later may become- relaxed and bathed with perspiration. There is often clonic convulsions. The pupils are generally contracted, and the conjunctiva injected. Grinding the teeth is a common symptom. Incontinence of urine and feces occurs in a number of cases. Vomiting and purging may occur, and are to be regarded as unfavorable symptoms.

Diagnosis.—The circumstances under which the attack comes on, and the characteristic symptoms noted, render the diagnosis. comparatively easy.

Prognosis.—In the severer forms of the disease, especially if not seen early, the mortality is high. Many cases recover slowly, and weeks or months elapse before the patient entirely recovers his mental and physical equilibrium. In some cases, the patient is never able to stand high temperature after once undergoing heat-stroke.

Treatment.—Prophylactic measures should be encouraged during the heated term. Alcoholics, and especially beer-drinkers, should be cautioned as to the danger of drinking stimulants during excessively hot weather, and those working in the sun should wear light clothing, and place a wet cloth or green leaves, preferably cabbage-leaves, in the hat. If dizziness is noticed, or the person exposed finds perspiration scanty or absent, he should immediately suspend work and seek the shade.

If the attack is mild, there may be only need for stimulants to overcome the sense of prostration. Belladonna, nux vomica, cactus, carbonate of ammonia, strychnia, and like remedies will be used as they may be indicated.

In a more severe case, and where the temperature is very high, strip the patient of all clothing, and sponge him with hot water, at the same time have two or more assistants fan him vigorously. Any one who has not pursued this course will be surprised how rapidly the temperature will be reduced. The sponging with hot water determines the heat to the surface and the fan secures rapid evaporation. Aconite, rhus, gelsemium, and such sedatives as may be indicated should be given, but as a temperature-reducer, nothing equals the sponging with hot water, and the vigorous use of the fan. For nausea, an infusion of neutralizing powder with a little brandy, or bismuth and mint-water, rhus tox., ipecac, or peach-tree infusion, will be found beneficial.

The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.