Mínimum criteria in deprivation of liberty These means should cover all departments in which minors may remain (other than rooms and toilets) and, very particularly, at places used for their contention. 303. Minors should be afforded adequate communication with the exterior world. The NPM considers that all possible means should be put in place for the purpose, since such communication is an inseparable part of the right to fair and humanitarian treatment and benefits the integration of these minors into society. A system of calls to family relatives and friends should be set up, the cost of which should be borne by the centre and at which the privacy of such calls should be respected. Relations with the family of the juvenile should be permitted and facilitated, unless a court decision otherwise is issued, their frequency to be established in the individual project, and such frequency may only be limited where so decided by the judge. 304. It is considered necessary, in general, to give particular attention to compliance with legislation relating to the adaptation of the facilities, prior to the approval of any project that implies affording minors shelter. Thus, the enabling of new resources that do not meet suitable conditions for implementation of the project in question should be avoided. 305. Centres should have, to the extent possible, large areas permitting sports and outdoor leisure activities. 306. Special attention should be given to the lighting conditions in common halls and rooms, encouraging natural light, and evaluating the temperature existing in the centre throughout the year, in order to avoid excessive oscillations, adapting it to the weather and station of the year. Attention should also be paid to ensuring an adequate ventilation of indoor areas. 307. All centres should have a centralised mechanical opening system for the doors to the rooms, to ensure emergency evacuation if necessary, and have interphones or lighting or sound calling systems within them, for minors to be able to request the immediate assistance of personnel of the centre if necessary. 308. Centres should ensure that all minors have available adequately prepared and served food at the usual times, meeting quality and quantity conditions satisfying diet, and health and safety rules, with special diets for medical, religious or cultural reasons, and access to drinking water at all times. 309. Religious and cultural beliefs, and moral practices and provisions of minors should be respected. 310. The ongoing supervision of centres of this kind by the responsible authority is of great importance. 103