This paper explores interpreting practice in the field of emergency medicine. The analysis is conducted on a corpus of tape-recorded interpreter-mediated encounters between the medical staff of an Italian hospital and English-speaking tourists. The specificity of the setting – an Accident & Emergency Ward – where patients are not member of a minority community, but feel nonetheless vulnerable because the emergency has occurred away from home, as well as the unusual profile of the interpreters who are employed on a seasonal basis as “administrative assistants”, make this study an atypical investigation into public service interpreting. Through the use of different theoretical approaches it is demonstrated that asymmetry in medical encounters is the product of a complex set of factors. More specifically, it is a shifting variable which is locally and interactionally determined through successive turns at talk by all interlocutors, doctor, patient and interpreter alike. The latter, in particular, is seen to behave as a fully-fledged social actor who makes independent choices on the basis of his or her assessment of the goals and requirements of the ongoing activity.