frequent basis to ensure that there is a continuing need for them. The longer a restriction is imposed on a prisoner in remand custody, the more rigorous should be the test as to whether the measure remains necessary and proportionate. 64. The material conditions and the detention regimes provided to inmates held in solitary confinement must meet the standards laid down by the CPT;13 in particular, prisoners should be provided with appropriate human contact throughout the duration of the measure and the prison authorities should make every possible effort to alleviate the potentially damaging effects of solitary confinement on the prisoner concerned. 3. Juveniles on remand 65. In principle, the remarks made in the preceding sections also apply to juveniles. However, in the CPT’s view, there are a number of specific standards which should be taken into account when dealing with juveniles in remand detention. These standards are set out in more detail in the 24th General Report on the CPT’s activities.14 For ease of reference, the Committee wishes to recall certain key aspects which deserve particular attention. 66. First of all, it is a well-established precept that, in all action concerning juveniles, their best interests shall be a primary consideration and they should only be deprived of their liberty as a last resort and for the shortest possible period of time.15 67. Further, the CPT considers that detained juveniles who are suspected (or convicted) of a criminal offence should, as a rule, not be held in institutions for adults but in facilities which are specifically designed for persons of this age group, offer a non-carceral environment and a regime tailored to their specific needs and are staffed by persons trained in dealing with juveniles. Regrettably, in many Council of Europe member states, it remains the case that juveniles on remand in particular are frequently held in prisons for adults. The CPT acknowledges that, in such cases, juveniles are nowadays usually accommodated separately from adults, often in a designated unit. In addition, significant improvements have been observed in recent years in terms of material conditions in juvenile units. However, in a number of countries, the regime offered to juvenile remand prisoners held in adult prisons still leaves much to be desired, especially in remand establishments which usually accommodate only very small numbers of juveniles (in particular female juveniles). On several occasions, the CPT observed that only one juvenile was 13. 21st General Report on the CPT’s activities (CPT/Inf (2011) 28), paragraphs 53 to 64. 14. See paragraphs 96 to 132 of CPT/Inf (2015) 1 (Juveniles deprived of their liberty under criminal legislation). 15. See Articles 3 and 37.b of the United Nations Convention on the Rights of the Child and Rules 5 and 10 of the European Rules for Juvenile Offenders; see also Rule 13.1 of the United Nations Standard Minimum Rules for the Administration of Juvenile Justice (Beijing Rules), Rule 17 of the United Nations Rules for the Protection of Juveniles Deprived of their Liberty (Havana Rules) and the 2010 Guidelines of the Committee of Ministers of the Council of Europe on child friendly justice. General Report of the CPT, 2016 ► Page 36