2 Edinburgh Med. Journ., vol. xiv. p. 1029, 1864.
Although the immediate cause of the attack is excessive heat, there are certain conditions which act as predisposing causes by lessening the power of the system to resist the heat, or, in accordance with the theory of sunstroke which I believe established, by so weakening the inhibitory heat-centre that it is readily exhausted. The chief of these predisposing causes are race, excessive bodily fatigue, and intemperance. It is true that males are much more frequently affected than females; thus, in an epidemic occurring in St. Louis, Missouri, in 1878, there were 115 deaths in males and 39 in females. This is due, however, not to one sex being predisposed to the attacks, but to the habitually greater exposure of males than of females to heat. The much greater frequency of sunstroke in the laboring than in the upper classes has similar explanation.
Those races which are least accustomed to a tropical climate are most apt to be attacked; thus, both in this country and in India, Europeans suffer far more than do the natives. No race is, however, absolutely exempt. Even the negro and the Hindoo inhabitant of tropical India are occasionally prostrated.
The general experience in the United States shows that habitual excess of alcohol very strongly predisposes to attack, but some of those who have had widest experience in India are inclined to deny this. It has been especially noted in India that persistent bodily fatigue greatly weakens the resisting power of the European. As an instance of this may be cited the case of the Forty-third regiment of the line during the Sepoy rebellion, as recorded by its surgeon, Barclay. It had made a most extraordinary march of over eleven hundred miles, chiefly through the lowlands of India, and at the hottest season of the year. This march was continuous, with the exception of a few brief halts. No cases of sunstroke occurred until nine hundred and sixty-nine miles had been traversed and the men had become thoroughly exhausted and even markedly emaciated. Shortly after this the regiment rested some eight days, and then started again, arriving soon in a narrow ravine in the Bisramgunge Ghat, with precipitous walls nearly a mile in height. During the day the thermometer in the tents ranged from 115° to 127°, and on one occasion was noted 105° at midnight. The number of cases of insolation now became very great, and, although most of them recovered, 2 officers and 11 men were lost in the four days during which the regiment remained encamped. The air became cooler as the command emerged from the hills, yet 7 more fatal cases occurred in three days.
SYMPTOMS.—Under the name of ardent continued fever, or febris continuis communis, has been described in India an affection which may be considered as representing a mild form of thermic fever. In C. Morehead's clinical work On the Diseases of India the following account of the symptoms is given: “The attack is generally sudden, often without much chilliness. The face becomes flushed; there are giddiness and much headache, intolerance of light and sound. The heat of skin is great; the pulse frequent, full, and firm. There is pain of limbs and of loins. The respiration is anxious. There is a sense of oppression at the epigastrium, with nausea and frequent vomiting of bilious matters. The bowels are sometimes confined; at others vitiated discharges take place. The tongue is white, often with florid edges. The urine is scanty and high-colored. If the excitement continues unabated, the headache increases, and is often accompanied with delirium. If symptoms such as these persist for from forty-eight to sixty hours, then the febrile phenomena may subside, the skin may become cold, and there will be risk of death from exhaustion and sudden collapse. In most cases the cerebral disturbance is greater in degree, and in these death may take place at an earlier period in the way of coma.”
Until very recently the existence within the United States of this class of cases has not been recognized. But in a very able article in the Therapeutic Gazette of March 16, 1885, John Guiteras shows that the so-called typhoid fever of Key West is the disease described by Morehead.
In the Philadelphia Medical Times, vol. v. p. 664, C. Comegys calls attention to the cases of entero-colitis which are so abundant in the young children of our cities during the hot months. The immediate enormous rise of the mortality-rate among children which always accompanies a marked rise of temperature during July or August indicates very strongly that excessive heat is the chief factor in the production of the disorder. The symptoms may be summed up as high fever, dry tongue and mouth, rapid pulse and respiration, intense thirst, vomiting, purging of greenish, watery, fecal or serous matters with undigested particles of food, and more or less pronounced evidences of cerebral disturbance, such as insomnia, headache, contracted pupils, delirium, and finally coma. In some cases the bodily temperature rises before death to a point comparable with that it reaches in sunstroke of the adult. As pointed out first by Comegys, these cases are almost uniformly relieved by cold water used either, as Comegys himself employs it, in the form of cold affusions practised until the temperature of the child becomes normal, or, as, according to my own experience, is preferable, simple cold baths administered every two to three hours, with just sufficient vigor to produce the desired effect.
Thermic fever in the adult and in this latitude is usually first seen by the physician after the stage of insensibility has been reached. In many cases this condition comes on with great suddenness, but in other instances there are distinct prodromata, such as inaptitude and disinclination to exertion, vertigo, headache, confusion of ideas, great oppression or distress at the præcordia or epigastrium, and disturbances of the special senses. Swift has noticed a peculiar chromatopsia, the sufferer seeing everything of a uniform color, in most cases blue or purple, but in others red, green, or even white, and W. H. Kesteven3 has reported a case in which a man, after exposure to an excessively hot sun, was seized with severe headache, saw everything red or green, and had for some days a distinctly impaired color-sense.
3 Trans. Clin. Soc. of London, 1882, xv. 101.
At one period I saw a large number of advanced cases of sunstroke in the hospital, and the symptoms were quite constant. Total insensibility was always present, with, in rare instances, delirium of the talkative form, and still more rarely the capability of being roused by shaking or shouting. The breathing was always affected, sometimes rapid, sometimes deep and labored, often stertorous, and not rarely accompanied by the rattle of mucus in the trachea. The face was usually suffused, sometimes, with the whole surface, deeply cyanosed. The conjunctiva was often injected, the pupils various, sometimes dilated, sometimes nearly normal, sometimes contracted. The skin was always intensely hot, and generally, but not always, dry; when not dry it was bathed in a profuse perspiration. The intense burning heat of the skin, both as felt by the hand and measured by the thermometer, was one of the most marked features of the cases. The degree of heat reached during life was, in my cases, mostly 108°–109° F., but it sometimes reaches 112° F. The pulse was always exceedingly rapid, and early in the disease often not wanting in force and volume; later it became irregular, intermittent, and thready. The motor nervous system was profoundly affected: subsultus tendinum was a very common symptom; great restlessness was also very often present, and sometimes partial spasms or even violent general convulsions. The latter were at times epileptiform, occurring spontaneously, or they were tetanoid and excited by the slightest irritation. Sometimes the motor system suffered paralysis, the patient moving neither hand nor foot.