International sporting and mega-events such as London 2012 provide a pertinent case study through which to explore contemporary approaches to nationalism and cosmopolitanism. Using original focus group evidence from participants with expertise in the Olympics, this article provides an insight into how nationalist and cosmopolitan discourses emerge in dialogue between informed individuals set against an emotionally charged background. The evidence indicates that the transmission of emotions might be integral to the operation of nationalist but less so to cosmopolitan discourses, underscoring the conditional character of the latter discourses. Therefore, we suggest this takes previous work that associates nationalism with ‘hot’ emotions and cosmopolitanism with ‘cool’ emotions further. We found that most emotions appeared to be transmitted through challenges to, rather than in support of, a discourse. The opinions voiced in the focus groups are expected to be insightful for any investigation into the construction of nationalist and cosmopolitan discourses or, indeed, broader research into how emotions are actually transmitted – all of which have obvious relevance for social scientists interested in nationalism, cosmopolitanism and the role of emotions.