390 



DISEASES OF UNCERTAIN ETIOLOGY 



(2) Heat stroke : (a) Direct, with liigh body temperature after 



exposure to the sun ( =- sunstroke). 

 {b) Indirect, with high bodv temperature but 

 exposure to the sun is not necessary. 

 The difference between heat s}'ncope and heat stroke can be 

 tabulated thus (Bram) : — 



Heat Syncope 



(i) History of exposure to excessive heat, 

 usually indoors 



(2) Onset gradual, no convulsions or 



paralysis, but prodiomata as head- 

 ache, dizziness, nausea, &c. 



(3) Rarely, loss of consciousness 



(4) Skin cool, pale and clammy 



(5) Conjunctivas pale, pupils dilated or 



normal 



(6) Temperature normal, subnormal or 



slightly elevated 100"- 102° F. 



(7) Pulse weak and thready 



(8) Respiration shallow and sighing 



(9) Course greater in duration, pro- 



gnosis favourable, usually termi- 

 nating in recovery in a few days 



(10) Recovery usually uninterrupted and 



complete 



(11) Usually debilitated by disease 



Heat Stroke 



History of direct exposure to the sun's 



rays 

 Onset sudden, often with convulsions or 



paralysis 



Usually complete unconsciousness 



Skin hot, dry, flushed 



Injected conjunctivae, contracted pupils 



Temperature very high, io5'^-ii3'' F. 



Pulse high and bounding 



Respirations irregular, often Cheyne- 

 Slokes in type 



Course brief, with guarded prognosis, 

 terminating in death or recovery in 

 from a few hours to a day or more 



Complications and sequelae not uncommon 



Previously in normal health 



(1) HEAT SYNCOPE. 

 DEFINITION. 



Faintness or fainting as a result of exposure to a high atmospheric 

 temperature associated with humidity and bad ventilation in persons 

 whose bodies have been debilitated by disease. 



vETIOLOGY. 



The two necessary factors are ; — 



(i) High wet bulb temperatures. 



(2) Abnormal bodily health. 



This latter includes any organic disease, especially chronic 

 alcoholism A\hich causes fatty degeneration of the heart's muscle, 

 allowing dilatation under conditions of moist hot air in badly ventilated 

 places. Unsuitable clothing and vigorous exercise also predispose. 

 Alcoholism is the most potent factor. 



SYMPTOMATOLOGY. 



The patient may be in a badly ventilated building as a theatre or 

 church, in a crowd, or wearing unsuitable clothing as soldiers on the 

 march, or unduly fatty. The patient becomes giddv, staggers and 

 falls. There is pallor, small pulse, dilated pupils, shallow breathing. 



