Scenes of "mass contamination" are often scenes of collective hysteria, with hundreds or thousands of victims in a state of panic. Therefore, mass decontamination may require police, security, or rescue supervision to help control panic and keep order. Under these circumstances, mass decon can take on some features of mass arrests, with victims forcibly rounded up, then treated inside impromptu detention areas. Successful municipal decontaminations are greatly aided by a close collaboration between police and fire departments. An organised, informed and aware populace can be better prepared for possible emergencies, and is less likely to panic. In some situations volunteers may be needed to augment or replace rescue/security personnel to help maintain calm and/or assist with decontamination procedures.