HEAT SYNCOPE 



1459 



HEAT SYNCOPE. 



Synonyms. — ^Heat exhaustion, prostratiothermica. 



Definition. — ^Heat exhaustion is a condition of syncope brought 

 about by action of high air temperatures, especially if associated 

 with a considerable atmospheric humidity, upon persons whose 

 bodily health or conditions are abnormal. 



Climatology. — ^The climatology is the same as for thermic fever. 



^Etiology. — ^Two distinct factors are necessary for the development 

 of this condition: — 



1. High wet -bulb temperatures. 



2. Abnormal bodily health or conditions. 



The first factor has been sufficiently explained, but a word or two 

 about the second is necessary. The second factor consists of any 

 organic disease or chronic alcoholism, especially the latter, which 

 is apt to cause fatty infiltration and degeneration of the heart wall, 

 thus allowing dilatation of the organ under the stress of high air 

 temperature. 



This second factor also includes unsuitable clothing and too 

 violent exercise, which under high wet-bulb temperatures are 

 especially liable to induce syncope. 



But alcohol is by far the most important predisposing cause, and 

 accounts for the difference in mortality of expeditions in which 

 soldiers are allowed to drink it and those in which they are not. 



Morbid Anatomy. — ^As was shown by Pfeiffer in 1851, the heart 

 may be flaccid and very much softened, and full of blood, especially 

 on the right side, but apart from this there is little morbid change. 

 There may be congestion of the brain, lungs, and other viscera, but 

 generally there is little to note. 



Symptomatology. — ^The symptoms begin suddenly by the person 

 feeling very giddy, and sometimes sick and weak. If he attempts 

 to walk, he staggers, and may fall. He is pale, his pulse small and 

 soft, his pupils dilate, and his skin is cold. The temperature is 

 subnormal, or there may be a transient initial rise, 100° to 102° F., 

 and there may be loss of consciousness, but this does not always 

 take place. There is often considerable pain in the head. 



Generally the condition is quickly recovered from, sometimes 

 after a little sickness or fever, but at times it deepens into uncon- 

 sciousness, and ends in coma and death. 



Treatment. — ^When a person complains of feeling faint, lay him 

 flat on his back in as cool a place as can be found, and loosen his 

 clothing. Dash a little water on his head, face, and chest, and 

 give him a little brandy-and-water or sal volatile, if he can swallow; 

 but if he cannot, give a hypodermic injection of strychnine or of 

 ether and camphor. As soon as possible wrap the patient in 

 blankets, and apply hot bottles to various parts of the body. 



Prophylaxis. — ^The prophylaxis is the same as for thermic fever. 

 Giles advises nux vomica to be administered before hard work in 

 the sun. 



