BACKGROUND: Infectious disease outbreaks account for significant global costs in human lives, social implications, and financial burden. It is considered possible to minimise the consequences of catastrophic viral outbreaks through advance preparation and effective communication. To prepare effectively, it is important to understand the political, social, economic and cultural factors that impact on the epidemic spread and shape human responses and action. Despite the capacity of human emotions to influence all these issues, they have been largely neglected in public health. AIM: To ascertain if there are emotional determinants impacting population responses to infectious diseases outbreaks and understand how such emotions are influenced by the social and wider determinants related to the local context where outbreaks emerge. METHODS: A systematic review that explores the differences in public responses by emotion, infection, outcome and region, and five in-depth case studies of infectious diseases outbreaks at a national level to understand how responses are shaped by the local and global context of the time. FINDINGS: There are emotional determinants that influence public responses to epidemics and pandemics and impact on the uptake of interventions. To improve the effectiveness of public health communications in the face of emerging outbreaks, certain important messages emerged in my research, including the need to disrupt the power dynamics of “top-down” communications, build trust between global and local actors (as well as with governments), and harness the potential role of traditional media and social media for good and connection. Which emotions are evoked through public health communications is also important, as fear and panic were shown to be counterproductive in promoting uptake of interventions, but worry and empathy emerged as key motivators for action. CONCLUSIONS: Both in the context of the COVID-19 pandemic and for future emerging infectious diseases outbreaks, emotions need to be considered in crisis communications.