The Amazing You exhibition at the Tampa Museum of Science and Industry had over 400 different multimedia health exhibits. Visitors walked through life stages, from conception through death, the exhibits at first showcasing developmental milestones, then diseases and chronic conditions associated with ageing. Museum executives described the exhibition as a public health intervention that stressed disease prevention, screening and behaviour change. This piece considers the question: What makes an exhibition be a health intervention? To describe complexities of the communication environment I use a mnemonic device called SPEAKING, an acronym for ‘Scene/Setting, Participants, Ends, Act Sequence, Key, Instrumentalites, Norms and Genre’ (Hymes, 1974). This methodological tool from the ethnography of communication approach provides explanatory concepts from speech act theory, the interactional view of communication, and frame analysis. SPEAKING is an order of inquiry for understanding multimodal environments in museums, especially those that try to change behaviour. Using examples from exhibit descriptions and interviews, I consider the communicative dimensions of The Amazing You using SPEAKING. This work is intended for exhibitors, museum curators and researchers interested in informal learning and behaviour change.