-20 prisoners undergoing the same regime. This is a particularly problematic type of isolation. Very often the procedural safeguards for the protection of isolated persons are lower than those for disciplinary solitary confinement. Unlike the latter, there are very often no defined time limits, and in many cases it is prolonged for months and years. 2.1.4. Solitary confinement as a protective measure Solitary confinement is also used for protective purposes. In order to protect some groups of prisoners who might be endangered because of the crime they committed, because of their collaboration with the police, because of their sexual orientation or gender identity, or in some cases because they suffer from behavioural disorders that make it difficult to live with the rest of the prison population. Isolation for protective purposes may also involve, albeit for shorter periods, those who have attempted suicide or committed acts of self-harm, and often takes place on the decision of the health authorities. In cases where isolation is used as a protective measure by prisoners who feel threatened, alternatives should be found, and it should be possible for detainees to spend some hours of the day with others, or at a workplace or within activities where they are safe. 2.1.5. Voluntary solitary confinement Some jurisdictions allow the placement in solitary confinement at the request of a detainee. The reasons behind these requests are several: prisoners might not be able to receive protection from the prison administration in any other way, or it could be a reaction to overcrowded cells, and this might be the only way to have a single cell for oneself. Even in this case, it is important to remember that the detainee may still suffer from the detrimental effects of solitary confinement even when s/he voluntarily chose to be isolated, and it is important to look for alternatives. In all these cases when faced with a request for protection, the administration often responds with isolation. Instead of adding something in order to support the regime of a person in difficulty, the response goes in the opposite direction: solitary confinement.