Page:Popular Science Monthly Volume 3.djvu/514

500 the germs of disease in the excreta of the sick, and in both ways favors the spread of contagion.

Its direct action upon the person becomes most apparent when some of the functions are going wrong. When the body is healthy, and proper precautions are taken in its management, there is little to fear from exposure to heat. Observers in tropical countries tell us that excessive heats are borne with impunity by the healthy, and that it is mostly those who are either temporarily or chronically out of order that eventually suffer. Not that the body can bear unlimited exposure to great heat, any more than it can endure continuous exertion, but that it is capable of maintaining itself under even excessive heat, if the exposure is not too prolonged. When its powers are impaired by some local or constitutional complaint, however, and it is less able to do the extra work which the influence of excessive heat imposes, then is the time when even slight exposure may be followed by the most serious consequences.

Authors describe several forms of acute disease that are traceable to heat as the exciting cause, but, as all of these partake more or less of the nature of sunstroke, and as we are writing for the public rather than the physician, it is not necessary here to go into their distinguishing features. Sunstroke, or the disease hitherto passing under that name, though known since early times, is even yet not well understood. Up to within a few years, it was believed by patient and physician alike that, to produce it, the body, and especially the head, must be exposed to the direct rays of the sun. There is now abundance of proof to the contrary. In his admirable little work, entitled "Thermic Fever, or Sunstroke," Dr. H. C. Wood quotes the records of its occurrence in barracks, hospitals, and tents, and not infrequently in the night-time, in many cases without immediate previous exposure to the sun. According to Dr. Bonnyman, as cited by Dr. Wood, "By far the greater number of cases that yearly occur in India are of men who have not been exposed to the sun. It is not unusual for men to go to bed in apparent health, and to be seized during the night; and patients in hospitals, who have been confined to bed for days previously, are frequently the subjects of attack." Dr. Swift testifies to its production by exposure to artificial heat, eleven cases treated by him having been attacked in the laundry of an hotel; while several others occurred in sugar-refineries. Dr. Wood mentions a case of his own, which also originated in a sugar-refinery. Dr. Maclean, in the second volume of Reynolds's "System of Medicine," quotes M. Boudin to the effect that one hundred cases of sunstroke occurred on the French man-of-war Duguesne at Rio Janeiro, most of them at night while the men were lying in their bunks. Much more of similar import might be offered, but enough has been said to show that it is great heat which precipitates the attack, and that it makes little difference whether this come from exposure to the direct rays of the sun,