General: Safety, Health and Wellness, and Incident Management
Working inside the safety system
Questions in this domain rarely ask you to name a standard; they ask you to pick the correct action within NFPA 1500-style safety expectations, a NIMS/ICS structure, and a rehabilitation plan. Know that NFPA 1500 is the fire department occupational safety, health and wellness program standard; NFPA 1582 covers medical fitness; NFPA 1584 governs on-scene rehabilitation; NFPA 1404 governs SCBA use and air management; and NFPA 1403 governs live-fire training evolutions.
Two-in/two-out: when firefighters enter an IDLH atmosphere, at least two members must remain outside, fully equipped and ready to begin rescue, and that standby team must be in place before entry. Many departments call it a firefighter assist and search team (FAST) or rapid intervention team (RIT).
A Mayday is a firefighter in distress, not a civilian victim report. Transmit it with the group name and LUNAR (location, unit, name, assignment and air, resources needed). It outranks all other traffic and is normally followed by a personnel accountability report (PAR) for every crew, not just the affected one.
Command: the first-arriving company officer establishes command. Transfer of command requires a briefing covering situation, objectives, actions taken, organization, and resources, announced on the radio. Divisions are geographic; groups are functional. Span of control is three to seven, with five the effective number.
Trap: assuming a Mayday automatically triggers evacuation. It does not; requesting evacuation or declaring emergency traffic is a separate command decision.
Rule of thumb: if you cannot state your air status, you are not ready to transmit a Mayday.