The last decade has witnessed a growing interest in design information technologies and interfaces that support rich and complex user experiences, including satisfaction, joy, aesthetics, and reflection. It is high on the agenda to extend and intensify the overall (user) experiences with the help of appropriate technology. This paper presents two pilot studies in which mobile devices were used to enrich shared experiences by measuring user generated collective heart rate. It is visualised in the indoor ice rink and utilised in exertion games to bring intensiveness into the audience experience. The aim of the study was to explore the usefulness and affect of the developed collective heart rate system and to evaluate it as one of the new features that could enhance the shared experience among the audiences in co-creational spaces. In particular, the study focuses on studying the significance of the technological equipment in creating a sense of collectiveness and togetherness of the participants. This research is important because it introduces a new idea of user involvement with the techniques of mobile phones and heart rate measurement belts. The results, positive and negative, of the study widen the field of physiological sensing technologies and facilitate the diffusion of these techniques into different public events.