A robust baby who has been gradually accustomed to being out of doors during the day will usually be much benefited by sleeping out at night. But he must be protected from winds and his clothing so arranged that he cannot be chilled. Knitted or flannel sleeping garments or sleeping bags (See Fig. 20) are valuable and in addition, the blankets which cover the baby should be securely pinned to the mattress with safety-pins and tucked well under it at the sides and foot. The baby should wear a warm cap and the bed should be warmed before he is put into it. Or better still, he may be dressed for the night, put to bed in a warm room and the crib then moved out on the sleeping-porch. An excellent device for protecting the baby’s arms and chest, and keeping him generally well covered, is the poncho (Fig. 56) devised by Dr. Lucy Porter Sutton of Bellevue Hospital. The poncho is a rectangle made of flannel, outing flannel or an old blanket and cut large enough to tuck well under the head and sides of the mattress and extend below the baby’s feet. The baby’s head slips through an opening, which is almost a right-angled slit, equally distant from the sides of the poncho and about 20 inches from the top. The slit is firmly bound and provided with tapes to tie it together after the baby is put in. The poncho should be put on loosely enough to permit the baby to move about at will beneath it. After it is adjusted the bed is made up as usual with additional blankets. [Illustration: FIG. 56.—The “Sutton Poncho” which keeps even a restless baby well covered. The insert shows how to make the slit for his head to pass through. The regular bedding is turned back in this picture. (From a photograph taken at Bellevue Hospital.) ] Under all conditions the baby’s airings must be increased gradually, both as regards lowering the temperature and lengthening the time, and always adjusted to the vigor and reaction of the individual baby. He must be warm, but not too warm; he must be protected from wind and dust, and his eyes shielded from glare and from flickering light, such as may be caused by a tree in a light breeze. EXERCISING YOUR BABY