A mission in a polar station holds a particular place for people who chose to experience this situation. It not only constitutes a rupture compared to the “usual life”, but it also often corresponds to a transition in the life course. For example, the young scientists who operate in the French bases generally prepare to face for the first time their professional life at the end of their mission. In the same way, the other categories of workers often use this experience of isolation for a professional or personal questioning. To this long transition are added shorter ones, at the beginning and at the end of the winter-over. During these periods, people have to adapt to new situations: at the beginning of mission, they have to learn how to live in this new environment, and sometimes they need to change their ways of living and their behavioural norms. At the end of the mission, the approach of the return to the “real life” necessitates a psychological reorganisation of their relationships with the environment. Thus, we can identify three great periods during a winter-over, each one corresponding to a particular relationship with the social and physical environment. This is why the data collected at these three times can provide very different results. In the four French polar stations, we attempted to study these three periods and to consider how people manage both available space and interpersonal relationships that take place in it. These factors could constitute some indicators of adaptation in this situation. The most important methodological difficulty is related to the situation itself since we tried to preserve its socio-environmental characteristics, and to work with qualitative data, thus privileging the psycho-environmental approach. The choice of the methods is linked to the choice of the time when the data are collected: an external researcher can only intervene before of the real isolation period (i.e. the austral winter), and/or afterwards, and thus collect only either expectations, or the perception of a reformulated reality. In this case, we then worked using semi-directive interviews. On the contrary, the collection of data during the winter can be considered only with the assistance of a member of the wintering group, which causes usual problems of a participant observation. From this point of view, and in order to preserve objectivity, we choose to systematize this observation, and joined it with questionnaires during the mission. A three moments comparison gives interesting results by confronting perceptions (a priori and a posteriori) of wintering people with their behaviours during the mission. This communication will be based on two studies privileging one or the other of the methods (interviews at the beginning and at the end of a mission; and on site observations). We will show how it is possible to analyse, through the investigation of psycho-environmental aspects, different modes of adaptation to this type of “extreme” situation. At the beginning of winter-over, the analysis of perceptions and representations of the life in the station makes it possible to stress an utopian vision. It also gives information on the way in which information is transmitted from a mission to the next one. This transmission of information can also be put in obviousness during post-winter interviews. This kind of interview can also provide information on the way the situation has been lived by the subjects. It underlines for instance some kinds of environmental appropriation such as perceived by the subjects. The way they lived the situation is then, in the speeches, spontaneously confronted with their fears and waiting face to the end of the mission and the approach of the return to the “ordinary” life. It is then a way of tackling the possible problems associated with transitions in their life. Last, observations during the winter make it possible to have some specific behavioural information, and more specifically when and where (and with who) behaviours take place. It is then possible to stress usually non-declared elements during interviews: interpersonal and intergroup conflicts, privileged uses of certain places, and especially evolution of these behaviours during the mission. We then hypothesize that observed behavioural changes could be an indicator of a “rupture” or reorganization in the isolated life.