Annual Report 2014 of the National Preventive Mechanism 147. Lastly excessive temperature oscillations should be avoided at the centres, adapting the temperature to the weather and station of the year. III.3 Criteria to be met in facilities for long-term deprivation of liberty III.3.1 Penitentiary centres 148. At visits to CP special attention is given to eventual allegations of ill-treatment of inmates and the application of coercive measures and regimental limitations. However, many other aspects of the detention at penitentiary centres are examined, since they affect the living conditions of the inmates. 149. Despite the drop in the prison population of the past years, the excessive occupation observed in many Spanish CP is observed, implying an almost generalized breach of the legal mandate of the principle that one prisoner should exist per cell, is a matter of concern; other than in few exceptional cases, cells are doubled and in some cases inhabited by three, four or even more inmates. Cell with capacity for 7 inmates at the CP for women of Barcelona 150. A reason for great concern of the NPM are the statements made by inmates who have described that they were victims or witnesses of ill-treatment or incorrect actions on the part of the personnel. When complaints of this kind are received, the persons in question are requested to give their agreement for the Security and Justice Department of the Ombudsman’s Office to commence the relevant investigation which it commences with the Authority, if appropriate, to know the facts. Nevertheless, the inmates occasionally state that they do not wish to bring a complaint for fear of retaliation, this institution respecting their will in such respect. 68