This paper is an analysis of complex crisis management and the importance of resilience on the example of co-occurring disasters. A resilience framework model was analyzed based on epidemiologic data and the interplay of several disasters; the COVID-19 pandemic and two 2020 Zagreb, Croatia earthquakes. A dose-response principle may be applied to a complex crisis scenario, within a resilience-vulnerability framework. The available data present the concept of balance between vulnerability and resilience of the population affected by complex crises as well as possible adaptation mechanisms. Multiple disasters that last for a prolonged period reduce the populations’ resilience and increase the risk of the next crisis becoming a disaster as well. Such complex disasters should not be approached by multiple risk management protocols, but rather by a single, multilayered protocol. Health policies that predict the possible effects of complex disasters on health risk management need to provide measures to maintain and promote resilience instead of collapse. These is a clear need to adopt green environmental policies, reduce socioeconomic inequality, train volunteer managers during crises, introduce timely evidence-informed policies and transfer new research and innovations in society rapidly. •Analysis of crisis management on the example of the COVID-19 pandemic co-occurring with two earthquakes in Zagreb, Croatia.•Vulnerability and resilience offer explanations for the stimulating effects of optimal stress during crisis events.•Arndt-Schulz Law and Hans Selye’s general adaptation syndrome may explain complex disasters dynamics.•Balance between vulnerability and resilience affected by complex crises may be influenced with comprehensive health policy.