Sunstroke (otherwise called Heatstroke, Heat Apoplexy, Heat Asphyxia, Coup de Soleil, Erythismus tropicus, and Insolatio) is a very fatal affection of the nervous system, which seldom occurs in Great Britain, except in extremely hot summers, but is very common in India and other tropical countries. The symptoms of the disease are liable to be greatly modified in different cases. Two contrasted forms are recognised. In the cardiac the heart is chiefly affected, and the symptoms are weakness, faintness, dizziness, &c. Death may take place either suddenly or more gradually from failure of the circulation. If recovery occur it is complete. This form is said to occur only from direct exposure to the sun's rays. In the cerebro-spinal form, the commoner of the two, the symptoms usually come on more gradually; nausea and dizziness may be present at first; but the most striking feature of the disease is either wild delirium or coma, with a pungently hot skin and extremely high temperature—106° F. or upwards. Even those who recover from this form of the disease are apt to suffer for a long period, or it may be permanently, from severe headache, epilepsy, enfeebled mental power, or other nervous disorders. Intermediate varieties are also met with, forming links between these two extremes. The mortality from sunstroke is about 50 per cent. of those affected. In the cases that terminate favourably a gradual remission of the symptoms takes place; and when the skin becomes cool and moist, and sleep has been procured (phenomena which usually occur within thirty-six hours of the attack), the patient may be regarded as out of danger.
The predisposing causes of sunstroke are (1) an unusually elevated degree of temperature; (2) heavy or unduly tight clothing, particularly if it interfere with the free expansion of the chest; (3) a contaminated atmosphere from overcrowding; (4) all debilitating causes, such as prolonged marches, previous disease, intemperate habits, &c. Death sometimes occurs so suddenly that there is little opportunity for treatment, but the general indications in these cases are the cold douche, from a height of three or four feet, keeping the surface wet and exposed to a current of air, the exclusion of light as far as possible, and the free employment of stimulants. In less rapidly fatal cases the outer clothing should be removed, and the douche applied, as before, over the head and along the spine. Relaxation of the pupil is the first favourable sign. If the pulse flags the douche must be replaced by the mere application of cold to the head, and it may be necessary to apply hot bottles, &c. to the extremities. The hair must be cut short, and the nape of the neck blistered as speedily as possible. If insensibility recurs after an interval of ten or twelve hours, a blister should be applied to the crown of the head. The extremities and chest should be stimulated with mustard poultices. Immediately after the employment of the douche a strong purgative injection should be thrown up the lower bowel. Under no circumstances should there be any abstraction of blood. If injurious effects persist long after partial recovery, the patient should be removed to a cooler climate.
The preventive measures are of more importance than the treatment. There has occasionally been an extraordinary mortality from sunstroke in the United States in very hot summers.