The nature of these environments will almost certainly limit the number of responding personnel in the inner cordon, but incident commanders will still have to consider how to achieve the task using the minimum number of personnel.

Other considerations will be the arduous nature of the tasks and the environment in which they are carried out. The need to relieve personnel regularly and the extended travel time to the scene of operations must therefore also be considered.

See National Operational Guidance: Incident command - Establish appropriate cordon controls.