470 Our Surroundings 



woven and holds much air, is a poor conductor of heat and thus 

 retains the warmth of the body. It is worn in winter to protect 

 against too sudden changes of temperature and the colds which 

 result from them. Cotton, linen, and silk conduct heat away 

 from the body easily and so are good for summer wear. 



Industrial Hygiene. Industrial hygiene refers to the move- 

 ment for providing more healthful surroundings for those who 

 labor in factories, and for installing safety devices to protect 

 those who work where there is danger of injury. The importance 

 of this movement can readily be understood when it is borne in 

 mind that there are in this country many millions of wage earners 

 who spend from one-third to one-half of their lives in their places 

 of occupation, generally within doors. Many thousands of wage 

 earners are killed, and many more thousands are wounded by 

 industrial accidents each year, and there are millions of cases of 

 illness among industrial workers. 



Of course all the ills and disasters -that befall wage earners 

 cannot justly be said to be due to their occupations, but a large 

 number are. Laws requiring factory sanitation, limiting the 

 number of hours per day of required work, and forbidding the 

 employment of children have been passed by many states, and, 



where they are enforced, are an 

 effective means of reducing in- 

 jury and illness. 



School Hygiene. Too much 

 attention cannot be given dur- 

 ing school life to learning the 

 rules of health and to forming 

 health habits. In order to give 

 value to the teaching, the rules 

 taught should be constantly prac- 



Medical inspection in many 



cities has shown that a very large 

 number of children have one or more of the following disorders : 

 defective teeth, defective hearing or sight, tuberculosis of some 

 part of the body, adenoids or enlarged tonsils, enlarged neck 



