Alarm pendant use among older people is often framed as one of the rational responses needed to alleviate the escalating costs of an aging population. This paper draws on qualitative data with older people and their carers to explore the effect that supplementing, and in some cases substituting, ‘traditional’ forms of care with this technology, has on the lives of its users. While advocates argue that alarm pendants can support independence and ‘aging in place’, our analysis focuses on how social relations both mediates the functions of this device and in turn are mediated by them. In this we draw upon key theories in Science and Technology Studies (STS) and George Ritzer's McDonaldization of Society Thesis, specifically his conception of the ‘irrationality of rationalization’, to illustrate how rational systems often produce unanticipated and adverse outcomes. Our research reveals that in the case of alarm pendants, these can include low levels of efficacy, increased work for older people and their carers and feelings of dehumanization. We conclude by discussing the capacity of older people to resist processes of McDonaldization and irrationalization in later life.