• Force may be necessary for the prevention of crime, including crimes committed in detention, or to effect lawful arrest, but no force going beyond that may be used and any force used must be proportionate to the objective to be achieved. • The use of restraints (such as shackles) during detention can constitute a violation of the prohibition against torture, cruel, inhuman or degrading treatment or punishment under general international law as well as a breach of Articles 7 and/or 10(1) of the ICCPR. Similar considerations apply to non-voluntary solitary confinement. Medical treatment and facilities • Article 12 of the ICESCR provides that every person has the right to the enjoyment of the highest attainable standards of physical and mental health. • All persons in detention should have prompt access on request and free of charge to proper medical and dental care and treatment that is appropriate to them. • The denial of proper medical treatment and facilities (particularly to persons in detention) may constitute torture or cruel, inhuman or degrading treatment or punishment. • Where necessary, persons should be transferred to specialist medical facilities such as a hospital. • Practical standards have been developed in relation to medical facilities for psychiatric patients (see for example World Health Organisation Guidelines for the Promotion of Human Rights of Persons with Mental Disorders). Medical and scientific experimentation • Article 7 of the ICCPR gives as a particular example of torture or cruel, inhuman or degrading treatment or punishment, the subjection of a person, without his or her free consent, to medical or scientific experimentation. • International law has evolved so that any consent also has to be fully informed consent. 70