344 



RESPIRATION AND EXCRETION 



.^o 



do their work, perspiration may be stopped, and the heat from 

 oxidation held within the body. The body temperature goes up, 

 and a fever results. 



If the blood vessels in the skin are suddenly cooled when full of 

 blood, they contract and send the blood elsewhere. As a result a 



congestion or cold may follow. 

 Colds are, in reality, a conges- 

 tion of membranes lining cer- 

 tain parts of the body, as the 

 nose, throat, windpipe, or 

 lungs. 



When suffering from a cold, 

 it is therefore important not 

 to chill the skin, as a full blood 

 supply should be kept in it and 

 so kept from the seat of the 

 congestion. For this reason 

 hot baths (which call the 

 blood to the skin), the avoid- 

 ing of drafts (which chill the 

 skin), and warm clothing are 

 useful factors in the care of 

 colds. 



Hygiene of the Skin. — The 

 skin is of importance both as 

 an organ of excretion and as 

 a regulator of bodily temper- 

 ature. The skin of the entire 

 body should be bathed frequently so that this function of excretion 

 may be properly performed. Pride in one's own appearance for- 

 bids a dirty skin. For those who can stand it, a cold sponge bath 

 is best. Soap should be used daily on parts exposed to dirt. 

 Exercise in the open air is important to all who desire a good 

 complexion. The body should be kept at an even temperature 

 by the use of proper underclothing. Wool, a poor conductor 

 of heat, should be used in winter, and cotton, which allows of a 

 free escape of heat, in summer. 





A, blood vessels in skin normal ; B, when 

 congested. 



