In situ and mobile methodologies are increasingly popular within research into diverse geographies of health and wellbeing. These methodologies include data-gathering techniques and modes of analysis carried out with research participants as they experience and move through settings with the potential to shape both momentary and longer-term experiences of health and wellbeing. This methodological development is both a response to and reflection of wider methodological and theoretical thinking across human geography, especially in relation to mobilities, performative, co-productive, and active ways to access and produce knowledge. In addition, the past few decades have seen increased access to geo-spatial technologies and tools to both locate and record experiential place-based knowledge. Such methods are capable of producing important new knowledge concerning the emergence (or foreclosing) of health and wellbeing in and through place, yet they are often perceived as "risky," drawing researchers out of their traditional researcher-controlled environments. Based on discussions developed during and since a July 2018 in situ and mobile methods workshop, this paper discusses the benefits of negotiating the (at times) somewhat messy and unpredictable research encounters that can unfold through such methods. It incorporates examples from recent and ongoing doctoral and post-doctoral research in health and wellbeing using out situ (in situ outdoors) methodological approaches in Britain and Ireland - including go-along interviews, video ethnography, elicitation, and biosensing. Three core themes are presented, concerning the value of mobile and in situ methods in: (1) supporting an ethic of care; (2) attending to more-than-human dynamics of health and wellbeing; and (3) integrating matter and meaning in contemporary efforts to understand how health and wellbeing unfold and accrete in and through place.