The work of the little sweat glands is very important to your health. These glands are just as important as the kidneys, and if they did not do their work, you would die very quickly. If your body is covered with dirt, the work of these glands is seriously interfered with; and when the sweat glands are not doing their full amount of work, the kidneys must do more than their share. It is never right to make one part of your body do the work intended for another part. [Illustration: FIG. 34. A model bathroom.] When the body is dirty, not only are the sweat glands interfered with, but the little sebaceous (oil) glands become plugged up, and blackheads appear on the face and body. [Sidenote: Importance of bathing] In order that the various glands of the skin may be kept in good health, it is necessary for us to keep clean. To do this we wash our faces and hands and bathe our bodies. Someone may ask, "How often ought a person to take a bath?" The question cannot be answered, except to say, "Just as often as may be necessary for you to keep absolutely clean." Some people do not have to bathe as often as others, but no one can keep clean unless he takes a bath at least twice a week. [Sidenote: Hot or cold baths] Another question that is frequently asked is, "Is it better to take a bath in cold or hot water?" This is another question that cannot be answered in the same way for every person. A cold bath is more stimulating than a warm bath. If, after you have taken a cold bath and rubbed yourself briskly with a rough towel, the skin becomes red and warm, a cold bath is best for you. But if, after you have taken a cold bath and rubbed yourself for not more than ten minutes, the skin appears bluish and cold, a cold bath is not good for you, and you should not take it. A cold bath should always be taken in the morning, just after getting out of bed, and a warm bath should always be taken in the evening, just before going to bed. [Illustration: FIG. 35. A nail properly cared for, and a nail not properly cared for. Which should you prefer to have?] [Sidenote: How to care for the nails]