In which situation would firefighters likely use an air monitoring device?

• A. A routine check of air in a well-lit hallway.
• B. A training exercise with no hazards.
• C. A medical call where multiple victims have collapsed for an unknown reason.
• D. After the incident is resolved.

Answer: (C)

Air monitoring devices are used whenever there could be a hazardous atmosphere, providing real-time readings of oxygen levels and the presence of toxic or flammable gases so crews can enter safely and choose the right protective measures.

On a medical call where multiple victims have collapsed for an unknown reason, a dangerous or unknown atmosphere could be present (for example, carbon monoxide, natural gas, or other toxins). The air monitor helps responders quickly determine if the scene is breathable and whether special PPE or ventilation is needed before or during patient care, reducing the risk to both patients and firefighters.

In contrast, a routine hallway check in good light, a training exercise with no hazards, or a scene after the incident is resolved typically does not require air monitoring, because there’s no anticipated hazardous atmosphere to detect.