People. That’s what emergency response is all about. Helping people when they are in trouble.

To do so, emergency responders have to protect themselves first.

Professionals who are called in to deal with an emergency must be certain of their own personal safety. If they themselves aren’t protected, how could they ever rescue others?

After an incident, the hazard may linger for a long time. It may spread with the wind.

Decontamination, evacuation, fire investigation, clean-up work — all may require comprehensive personal protection.

Whatever the task, it is crucial to have the right protection for the right job. In this line of work, over-protection can be just as dangerous as not having enough.

Zones

The concept of a hot, warm and cold zone has been devised to signify the real danger to responders, and therefore govern the choice of personal protection.

HOT in this respect means unknown. In the hot zone, you don't know exactly what the danger is. The hot zone is usually very close to the centre of the incident and very soon after. It might be the source of an unknown chemical, biological or radiological hazard, for instance.

WARM in this context means a zone where hazard assessment is possible. That is, the nature and extent of the hazard is known.

COLD means that the area itself is not affected by direct exposure to contaminant, perhaps because of its distance from the centre of the incident or 'ground zero'. But this does not mean that the area is completely safe: wind conditions may change, for instance, and cause airborne hazards to drift into the cold zone. Another potential hazard is people who may have fled from the hot or warm zones, and who in themselves might bring the hazard into the cold zone.

For a simple illustration of the zones, click HERE.

Zones change

Don't forget that zones can change from one kind to another kind at any time. For instance:

Change for the better:

• A fire burns itself out.
• A chemical combines with another chemical and becomes harmless.
• A gas cloud becomes so dispersed that it is no longer harmful.

Change for the worse:

• The wind turns and blows the contaminant into unexpected areas.
• A chemical combines with another chemical and becomes even more hazardous.
• A biological hazard seeps into the city water supply.