The Hartford Consensus recommends that an integrated active shooter response should include the critical actions contained in the acronym THREAT:
In the immediate aftermath of a mass casualty event, some lives may be lost through caution. The standard approach has been to cordon off the zone of casualties, a wide “hot zone,” until it’s been ensured that all threats are suppressed. The Hartford Consensus suggested that the plan be modified to allow earlier access to victims outside the real hot zone, the location of the active shooter, or a possible bomb. Thus, agreement on new systems of integration and coordination between law enforcement and other teams of responders is needed to ensure the mutual understanding and sequencing of roles.
By compressing the “hot zone” with the two other zones of care, the “warm zone” and the “cold zone,” less time is lost and more time is made available to begin bleeding control techniques so that more lives are saved (see diagram right).
*Source: The Hartford Consensus. Improving Survival Strategies to Enhance Survival in Active Shooter and Intentional Mass Casualty Events: A Compendium. Published by American College of Surgeons, September 2015. www.facs.org/~/media/files/publications/bulletin/hartford%20consensus%20compendium.ashx. Retrieved July 25, 2016.