A/HRC/39/45 Detention conditions and treatment must not be such as to impede the ability to challenge the lawfulness of detention, and detention should not be used as a tool to discourage asylum applications. 39. All detained migrants must have free access to appropriate medical care, including mental health care.44 VII. Migrants in situations of vulnerability and/or at risk 40. Detaining children because of their parents’ migration status will always violate the principle of the best interests of the child and constitutes a violation of the rights of the child. 45 Children must not be separated from their parents and/or legal guardians. 46 The detention of children whose parents are detained should not be justified on the basis of maintaining the family unit, and alternatives to detention must be applied to the entire family instead. 41. Detention of migrants in other situations of vulnerability or at risk, such as pregnant women, breastfeeding mothers, elderly persons, persons with disabilities, lesbian, gay, bisexual, transgender and intersex persons, or survivors of trafficking, torture and/or other serious violent crimes, must not take place.47 42. Men and women in detention should be always separated unless they are a part of an immediate family unit. VIII. The prohibition of non-refoulement 43. The principle of non-refoulement must always be respected, and the expulsion of non-nationals in need of international protection, including migrants regardless of their status, asylum seekers, refugees and stateless persons, is prohibited by international law. 48 IX. Detention facilities 44. The detention of asylum seekers or other irregular migrants must not take place in facilities such as police stations, remand institutions, prisons and other such facilities since these are designed for those within the realm of the criminal justice system. 49 The mixing of migrants and other detainees who are held under the remit of the criminal justice system must not take place. 45. Whether a place where those held in the course of migration proceedings is a place of detention depends on whether the individuals held there are free to leave it at will or not. If not, irrespective of whether the facilities are labelled “shelters”, “guest houses”, “transit centres” “migrant stations” or anything else, these constitute places of deprivation of liberty and all the safeguards applicable to those held in detention must be fully respected. 50 46. If a State outsources the running of migration detention facilities to private companies or other entities, it remains responsible for the way such contractors carry out that delegation. The State in question cannot absolve itself of the responsibility for the way 44 45 46 47 48 49 50 36 See, for example, A/HRC/27/48/Add.2, para. 118 (d) (iii); and A/HRC/30/36/Add.3, para. 75. See A/HRC/30/37, para. 46; and A/HRC/10/21, para. 60. See, for example, A/HRC/36/37/Add.2, paras. 43 and 92 (j). See, for example, A/HRC/13/30/Add.2, para. 79 (f); and A/HRC/16/47/Add.2, para. 119. See Convention against Torture, art. 3; and Convention relating to the Status of Refugees, art. 33. See also opinion No. 5/2009; A/HRC/27/48/Add.2, para. 129; and A/HRC/27/48/Add.4, para. 130 (c). See, for example, E/CN.4/1999/63/Add.3, para. 30. See A/HRC/7/4, para. 43; and A/HRC/36/37, paras. 50–56. See also A/HRC/33/50/Add.1, para. 36.