A/HRC/37/50/Add.1 49. Thus, in the large facilities visited, the number of and/or hours of attendance of general practitioners was insufficient for the number of inmates. This shortcoming was even more acute in regard to dental care, which frequently could not be provided in accordance with the detainees’ needs. Psychiatric and/or psychological support was often not available at all or was not provided as a routine preventive measure. For example, the D-type closed prison in Diyarbakır had only one general practitioner and one dentist for a population of over 1,000 inmates. 50. While medical equipment and supplies were generally found to be adequate in the detention facilities, and treatment was provided free of charge, the Special Rapporteur received allegations that inmates with medical conditions requiring transfer to hospital were only transferred in groups, once a sufficient number of detainees requiring such transfer had been reached, thus making prompt access to the required medical care problematic. 51. While adequate treatment and isolation of contagious diseases seemed to be provided when required in individual cases, there seemed to be no specific programmes for the management of contagious diseases, HIV/AIDS or drug addiction, all of which frequently occur in detention facilities. 52. Sanitary and hygienic conditions observed in the facilities were generally satisfactory, though they were also affected by the predominant overcrowding. Often, 20 to 30 detainees had to share one toilet and one shower, without sufficient hot water for each detainee. 53. Nutrition appeared to be sufficient in all detention centres visited, both in terms of the quantity and quality of food provided and in terms of protein and vitamin content. Also, inmates had access to sufficient quantities of drinking water. 6. Situation in police holding cells 54. The Special Rapporteur is seriously concerned about the conditions of detention in police holding cells. Such cells are designed to hold detainees for a few hours, or at most for one or two days, but are clearly not adequate for holding detainees for longer periods. This has raised serious problems, in view of the extension of the duration of police custody to 30 days. The Special Rapporteur therefore appreciates the Government’s announcement during the interactive dialogue with the Human Rights Council on 2 March 2017 that, in the meantime, the extension is reduced to seven days, and urges its complete revocation without delay. 55. In the police stations visited, holding cells generally had only barred doors, and were often under 24-hour video surveillance, thus depriving inmates of the most basic degree of privacy. In some places, constant bright lighting caused inmates to lose their sense of time. Cells generally had no windows and were too small to hold inmates for more than a few hours, and sometimes detainees were held in groups of 20–30 persons in shared rooms of clearly inadequate size. Detainees shared toilet and shower facilities outside their cell, which could only be accessed upon request. In some facilities, inmates reported that their cells had not been heated at all until heaters were finally installed shortly before the Special Rapporteur’s visit. In some instances, mattresses and covers were allegedly only provided a few days before the Special Rapporteur’s visit, and the facilities had visibly been freshly painted. 56. Detainees in police stations had no access whatsoever to a yard, sunlight and fresh air, which may be acceptable for a few hours, but clearly is not for periods exceeding 48 hours. D. 1. Safeguards and prevention Emergency decrees and derogations from regional and international treaties 57. Following the failed coup, the Government declared a state of emergency and notified the Council of Europe on 22 July 2016 that it was derogating from the European Convention on Human Rights, without specifying any particular provisions. With effect 10