How does ICEMA define a multi-casualty incident (MCI)?

ICEMA defines a multi-casualty incident (MCI) primarily based on the number of patients that are involved. The correct choice states that an MCI requires 5 or more units and involves 10 or more patients. This definition is crucial as it helps emergency services and responders gauge the scale of the incident and mobilize the necessary resources and personnel effectively.

The importance of defining an MCI by the number of patients and units reflects the complexity and potential strain such incidents place on emergency response systems. When there are 10 or more patients, it signifies a level of incident complexity that requires coordinated response strategies and specialized management protocols involving multiple emergency medical services (EMS) units.

Other options do not accurately encapsulate the key characteristics that define an MCI. For instance, involving multiple hospitals or specific requirements like police escorts does not directly relate to the operational definition and response protocols that guide the primary actions taken during a multi-casualty incident. Understanding this definition enables responders to prepare appropriately for such events.