Starting from its definition in the 2015 European Agenda on Migration, the “hotspot approach” has been adopted in different border zones within the European boundaries. This specific border dispositive is framed within the discourses on security and humanitarianism, depicting what William Walters (2011) defines as the “humanitarian border”. Focusing on the role of the medical expertise, the article examines procedures and practices at work inside the hotspot. The functions of identification, classification and selection characterize this border technology as a filter to decelerate, block, reroute mobility trajectories. Based on a research fieldwork on the hotspot of Pozzallo, Italy, the contribution examines - through ethnographical fieldwork, in-depth interviews and analysis of bureaucratic artefacts - the activities of medical staff, their experiences and interactions within this complex border assemblage. The function of the medical expertise is thus unveiled as a biopolitical tool to bodies’ governance, in its double dimension of care and control. Concurrently, the “doctor-patient” relationship could give space to enact counter tactics by the subjects captured in this border technology.