MONITORING PLACES OF DETENTION : A PRACTICAL GUIDE FOR NGOS 44 The frequency of the visits also largely depends on the gravity of the protection problems encountered. In some cases, for instance, it can be a good idea to repeat a visit after a short period of time if the NGO fears, rightly or wrongly, that reprisals might be taken against the detainees who talked to the visiting team. 2. THE VISITING TEAM 2.1. Composition To monitor conditions of detention certain skills are needed, in particular in the fields of law and public health. The visiting team should thus comprise at least one person with a legal background and one with a medical background, preferably a doctor. Should the NGO not have such skills available when forming its visiting team, it should at least make certain that those carrying out the visits have been given a general grounding in these subjects by professionals. Other professional skills can also be very useful–for instance, those linked to psycho-social, organisational, and environmental engineering activities. The NGO should, as far as possible, try to maintain stability in the composition of the visiting team for a certain length of time. If the members of the team change too often, it will be difficult to establish a constructive dialogue with the persons deprived of their liberty and the authorities in charge of the places of detention.