What does the "Mayday" signal indicate in fire service terminology?

The "Mayday" signal is a critical communication term in fire service terminology that specifically indicates a firefighter is in distress and needs immediate assistance. This alert is used to convey urgency and the necessity for a rapid response to the situation, emphasizing that the firefighter's safety is at risk. When a "Mayday" is called, it triggers the appropriate protocols to ensure that help is dispatched quickly, and additional resources may be allocated to rescue the individual in jeopardy.

The other options do not reflect the nature of a "Mayday" signal. For instance, signaling that a fire has been successfully extinguished does not imply an emergency and is communicated differently. Being ready to resume operations indicates readiness rather than a plea for help, and calling for all personnel to evacuate the building relates to safety protocol and not to an individual’s distress. Thus, the use of "Mayday" is uniquely tied to an urgent plea for assistance amid critical situations in firefighting contexts.