VENTILATION, HEAT, : 'A < NI>, (JLCfTjEMNG - , ;, , , 99 



wet day. We ought to be very careful how we cool our 

 bodies when we are very warm. We are liable to catch 

 cold if we go from a warm room into the cold air without 

 putting on extra clothing. 



185. Heating houses. In cold weather we cannot keep 

 warm without warming the air, so that less heat will pass 

 off from the body. When houses were heated with open 

 fireplaces, there was a roaring draft up the chimney with 

 perfect ventilation, but the room was always cold only 

 a little way from the fire. Now we use stoves. They do 

 not use much air and so do not give much ventilation. 

 If they give off dust and gas, they may make the air bad. 



In many houses, a furnace in the cellar is used to send 

 heat through pipes to all the rooms. This gives a great 

 deal of ventilation and is a good way of heating. Steam 

 in pipes is also used to heat houses. This heats the rooms 

 well but does not afford any ventilation. When it is used 

 we must be careful to let in enough fresh air. 



Kerosene stoves, or other kinds of fire in which the 

 smoke and burned products do not pass off through a 

 chimney, are the worst ways of heating, for they not only 

 use the air but they also pour foul gases into it. 



186. The proper warmth of a room. The best tempera- 

 ture for a house is about 70 degrees F. This feels neither 

 too warm nor too cold. For a bedroom the temperature 

 should be 60 degrees F. or less. 



187. Clothing. Sometimes nature cannot keep us warm 

 enough in cold weather, or protect us from the heat of 

 summer, and so men protect themselves with clothing. 

 In cold weather our object is to keep the heat from pass- 

 ing off from the body, and we wrap ourselves in thick 

 clothes. Clothing simply keeps in the heat of the body 

 without adding any new heat. 



