which, to all appearance, result exclusively from exposure to the direct rays of the sun. These cases might be classified under the term sun-traumatism.
Although not all of them are strictly classifiable as fevers, in deference to custom and for convenience I shall describe these three phases of so-called "heat-stroke " in this place and as a group.
HEAT-EXHAUSTION
Definition.— Sudden faintness, or fainting, brought about by exposure to high atmospheric temperature.
Etiology.— The healthy human body, when untrammelled by unsuitable clothing, when not exhausted by fatigue or excesses, when not clogged by surfeit of food, by alcoholic drinks or by drugs, can support with impunity very high atmospheric temperatures. In many parts of the world men live and work out of doors in temperatures of 100° or even of 120° F. Many industries are carried on at temperatures far above this ; glass-blowing, sugar-boiling, for example. The stokers of steamers, especially in the tropics, discharge for hours their arduous duties in a temperature often over 150° F.
When, however, the physiological activities have become impaired by disease, especially by heart disease, kidney, liver, or brain disease, by malaria, by alcoholic or other excesses, by fatigue, by living in overcrowded rooms ; or when the body is oppressed by unsuitable clothing; or in the presence of a combination of some of these, then high atmospheric temperatures are badly supported, the innervation of the heart may fail, and syncope may ensue. Chevers, than whom few have had better opportunities of forming a sound opinion, speaking of this subject, says: " Numerous as the constitutional causes of heat-strokes are, all Indian experience combines to show that drunkenness is the chief." The tropical practitioner will do well to bear this remark in mind; it applies not only to heat- exhaustion, but also to all forms of disease grouped under the term "heat-stroke."
