Hazmat control zones include
The cold zone
This is where incident command, personnel staging, EMS and medical monitoring operate. There is no need to wear any special protective clothing.
The warm zone
This is the transition zone between hot and cold. The most important function of this zone is decontamination. Patients will be brought to you from this zone (do not go into it unless you are part of HazMat).
The hot zone
This is the immediate area surrounding the release, and is contaminated. Only the persons necessary should respond in this area, all of whom should be trained as HazMat specialists.