0031-0330 irl.qxd 2.3.2009 14:20 Page 199 PROTECTION OF CIVILIAN PERSONS 199 The clothing supplied by the Detaining Power to internees and the outward markings placed on their own clothes shall not be ignominious nor expose them to ridicule. Workers shall receive suitable working outfits, including protective clothing, whenever the nature of their work so requires. CHAPTER IV Hygiene and Medical Attention ART. 91. — Every place of internment shall have an adequate infirmary, under the direction of a qualified doctor, where internees may have the attention they require, as well as an appropriate diet. Isolation wards shall be set aside for cases of contagious or mental diseases. Maternity cases and internees suffering from serious diseases, or whose condition requires special treatment, a surgical operation or hospital care, must be admitted to any institution where adequate treatment can be given and shall receive care not inferior to that provided for the general population. Internees shall, for preference, have the attention of medical personnel of their own nationality. Internees may not be prevented from presenting themselves to the medical authorities for examination. The medical authorities of the Detaining Power shall, upon request, issue to every internee who has undergone treatment an official certificate showing the nature of his illness or injury, and the duration and nature of the treatment given. A duplicate of this certificate shall be forwarded to the Central Agency provided for in Article 140. Treatment, including the provision of any apparatus necessary for the maintenance of internees in good health, particularly dentures and other artificial appliances and spectacles, shall be free of charge to the internee. Medical attention ART. 92. — Medical inspections of internees shall be made at least once a month. Their purpose shall be, in particular, to supervise the general state of health, nutrition and cleanliness of internees, and to detect contagious diseases, especially tuberculosis, malaria, and venereal diseases. Such inspections shall include, in particular, the checking of weight of each internee and, at least once a year, radioscopic examination. Medical inspections