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Category: EMS Operations

Topic: Scene Size Up

Level: EMT

7 minute read

There will be times when responders are confronted with more than one patient for a given incident. Upon receiving a call for service, responders should attempt to determine if there are multiple patients. The type of incident and description of the call should alert responders to this potential, i.e., motor vehicle collisions, any call involving mass transportation systems, calls at schools, or nursing homes.

While receiving a call involving any of these don't necessarily indicate multiple patient situations, it is imperative to gain as much information about the call prior to arrival to determine if multiple patients may be present.


Multiple-Patient Situations

When presented with a call involving multiple patients, responders should attempt to determine

  • the number of patients involved and
  • whether additional resources will be needed prior to arrival.

The dispatch system should be queried to help identify the number of patients present, additional hazards, and other pertinent information related to the incident.


Furthermore, a thorough size-up of the scene and preparations for the day will help responders determine extraordinary protections that may need to be implemented for patients.

That is,

  • Will protections need to be implemented for extreme weather conditions?
  • Are there unstable conditions that require responders to perform shoring or other stabilizing techniques prior to patient assessment or treatment?
  • Are the necessary resources immediately available to handle unstable or special situations?
  • Will additional resources be needed to accomplish any of these tasks?

It may be necessary to protect patients for extended periods if resources are not immediately available.


Attention must be given to bystanders during events because preventing injury to them is also a responsibility of responders. There are many ways to perform this task: 

  • Bystanders may be removed from the incident location.
  • Additionally, they could be isolated or they can be barricaded from the incident.


Prior to arrival, responders should make a conscious decision to determine if additional resources are needed.

If responders suspect that additional resources will be needed,

  • they should be requested early as they can be canceled at any time if not needed once the scene is assessed. Better safe than sorry!
  • Upon arrival, responders should recognize and identify the number of actual or potential patients.

If a mass casualty incident is present, arriving responders will need to triage patients and determine the level of additional resources needed if not previously requested.

Incident Command System: It is good practice to work within the Incident Command System on every incident responders encounter regardless of complexity.

Since the Incident Command System is scalable, this allows responders to become comfortable with the system and to practice how the system works on smaller-scale incidents.

By establishing command and communicating within the Incident Command System, responders will have a greater understanding of how that system fits within the larger framework of the National Incident Management System on complex events.