What defines a "mass casualty incident"?

A mass casualty incident is characterized by an event that results in a large number of patients requiring immediate medical treatment. This definition is pivotal because it highlights the need for an organized and scalable response to manage the overwhelming demand for medical resources and emergency services.

In such situations, the healthcare system can become strained, necessitating a coordinated effort that may extend beyond local resources to regional or even national levels. This response may include triage systems to prioritize care, as the number of victims can far exceed the available emergency personnel and equipment.

By contrast, an event with minimal injuries indicates a situation that does not overwhelm resources, and similarly, an incident affecting only one person does not meet the criteria for mass casualties. Lastly, incidents occurring in controlled environments typically involve circumstances where conditions can be managed and are not indicative of the chaotic nature of mass casualty incidents, where immediate and potentially life-saving interventions are urgently required due to the volume of patients.