138 



TEMPERATURE AND HUMIDITY 



fellow-passengers as took an interest therein, when passing through 

 the Red Sea in the hot months thereof. 



The air of the engine-room in steamers is laden with aqueous 

 vapour, and certain corners can be found near the condensers with 

 high air temperatures and practically no draught — or, in other 

 words, with conditions analogous to those under which Haldane 

 performed his experiments which we have mentioned in Chapter III. 



When the steamer is in the hottest part of the Red Sea in a warm 

 month, if a person, lightly clad and in good health, places himself 

 in such a comer, with a clinical thermometer in his mouth, it will be 

 found that at first he begins to sweat violently, and for a time remains 

 at a normal temperature. But in due course his temperature will 

 gradually rise and his pulse-rate increase, until temperatures of 

 over 102° F. are reached, and the person breaks off the experiment 

 because he feels uncomfortable, after which his temperature slowly 

 returns to normal. 



We have performed this simple experiment several times, but on 

 one occasion, in a person who was not in very good health, the 

 temperature, after reaching ioi° F., ceased to rise; the skin became 

 cooler, the tension of the pulse altered remarkably, and he began 

 to look ill. The experiment was quickly stopped and stimulants 

 administered, so that he did not suffer any serious effects, though 

 it was some hours before he felt quite right. 



These two experiments show that a high atmospheric tempera- 

 ture can act in two ways. In the first there was a gradual rise of the 

 body temperature, which, if continued long enough, would probably 

 have resulted in hyperpyrexia. In the second, after an initial rise, 

 the heart became embarrassed, and if the heat had been continued, 

 there appears no reason to doubt that this person would have 

 passed into a condition of syncope. 



There are, therefore, two distinct clinical entities to be considered 

 — viz., heat-stroke, characterized by high bodily temperature; 

 and heat-syncope, in which there are symptoms due to cardiac 

 failure but no fever, both of which are brought about by the same 

 cause — viz., high atmospheric temperatures associated with 

 moderate or high humidity. 



Such are our views ; but it is as well for the reader to be acquainted 

 with those of other authors, which may be briefly stated in an 

 historical account as follows : — 



High air temperatures, whether in the day-time or at night, have been 

 known since ancient times to have an effect upon human beings. The case of 

 the child of the Shunamite woman described in the EngUsh Bible in 2 Kings iv., 

 from verse 18 onwards, is probably the earliest on record. The child com- 

 plained to his father of his head when out with the reapers, and was carried 

 to his mother, and is reported to have died at twelve noon — became insensible 

 — but recovered under Elisha's treatment, which appears to have been of the 

 nature of massage. This treatment reminds one strongly of the active 

 friction by which the miners of the Comstock Silver Mines of Nevada are said 

 to treat successfully those of their fellows who faint when coming out of the 

 warm mine in which the hot, steamy air has a temperature of 128° F. 



It has been said that though old writers such as Dio Cassius described these 



