"Planning the EMS [Emergency Medical Services] components of a special (planned) event should be integral to any jurisdiction's or agency's planning process. While having an ambulance on standby may be appropriate for some smaller events, and many nongovernmental agencies will set up first-aid stations to support an event, involving all components of the EMS system in the plan is critical for a smooth operation when something is outside the normal expectations."
Coffee Break Training - Emergency Medical Services Series No. EMS-2013-5
United States Fire Administration: http://www.usfa.fema.gov/