Integration of volunteers and public: organisations and communication channels, possible functions, procedures

People affected by an extra-ordinary public health challenge (EOPHC), e.g. in situations of mass emergencies or disasters, cannot be reduced to the status of (passive) victims or to irrationally acting or panicking crowds. Even a well-prepared and coordinated Health Emergency Management System (HEMS) cannot control or anticipate the dynamics resulting from the decisions, actions and reactions, needs, demands and perceptions, as well as of the healthcare-seeking behaviour of people affected by an emergency.  In a mass emergency, uninjured, slightly injured, even some seriously injured survivors, their relatives present on-scene as well as bystanders or witnesses do not passively wait for (external) emergency assistance and the arrival of first responders. They take actions on site and move to hospitals nearby or even further away. This behaviour adds even more challenges to the health system and requires flexible adaptations in the health response.  Furthermore, events resulting in an EOPHC do not only have adverse effects on the health status of a community, but may - even temporarily - increase feelings and acts of solidarity and incite collaborative attitudes, contributing to disaster resilience.