SUNSTROKE AND SOME OF ITS SEQUELS. 173 



of impending evil, hurried and shallow breathing, disturbance about 

 the heart, gasping, giddiness, headache, occasionally nausea or vom- 

 iting, thirst, anorexia (want of appetite), feverishness, which soon 

 amounts to fervent heat of skin ; the surface may be dry or moist, 

 the pulse varies ; and these conditions gradually become aggravated 

 and frequently are worse at night, when the patient passes into a state 

 of unconsciousness and dies. 



The symptoms point to a profoundly disturbed state of the cerebro- 

 spinal nerve-centers, and to pathological changes in the organs whose 

 functions have been so greatly disturbed. 



Death is caused by asphyxia and apnoea, and in some cases probably 

 by cerebral haemorrhage. Recovery is often incomplete, resulting in 

 permanent impairment of health, and generally in intolerance of heat 

 and of exposure to the sun. These morbid conditions being due to 

 heat alone, are liable to occur whenever there is exposure to a high 

 temperature, whether solar or artificial. Soldiers marching or fight- 

 ing, when oppressed by weight of clothing or accoutrements, are apt 

 to suffer either from simple heat-exhaustion or from that form of 

 insolation which results from direct action of a powerful sun on the 

 head and spine. Soldiers, laborers, artificers, and people in factories, 

 heated rooms, hospitals, barracks, tents, and even ships, may suffer 

 from heat-exhaustion, which may pass into the same dangerous 

 condition of heat-asphyxia. People in the hay-field, or otherwise 

 exposed to great heat, especially if they have indulged in excess of 

 alcoholic stimulants and food, may suffer. Weak persons with defec- 

 tive hearts may die in this state of syncope. Soldiers or others, when 

 exposed to great heat, may drop out of the ranks, fall in a state of 

 syncope and die on the spot, or pass into a state of coma and die later ; 

 or they may recover, after being in great danger, with damaged nerve- 

 centers, and are rendered quite unfit for further service, or even resi- 

 dence in a hot climate. These cases occur on exposure to the direct 

 action of the sun's rays when the atmospheric temperature is also high, 

 and especially when unusual exertion is made, or when the individual 

 is depressed by previous illness or the exhaustion due to dissipation, 

 intemperance, or even undue indulgence in stimulants. 



But the most serious cases are those that come on under cover by 

 night as well as by day, and apart from the direct solar rays. Heat 

 alone, especially when the atmosphere is loaded with moisture so as to 

 prevent evaporation from the person, is the real cause of the disease. 



Vigorous, healthy persons of moderately spare frame, with sound 

 viscera, and who are of temperate habits, if the atmosphere be pure 

 and moderately dry, can sustain a great amount of heat. Acclimatiza- 

 tion has also some influence in conferring toleration. Fresh arrivals 

 in the tropics are more prone to suffer than those who have become 

 accustomed to the climate, and have learned how to protect them- 

 selves. It is well known that a native can bear an amount of sun on 



