What is the highest priority action when a MAYDAY is called?

When a MAYDAY is called, the highest priority action is to cease all radio traffic except for the MAYDAY. This ensures that the communication channel remains clear for critical information related to the emergency. The urgency of a MAYDAY indicates that a firefighter is in distress and requires immediate assistance; therefore, it is crucial that the response to this situation is not hindered by other radio conversations.

By silencing non-emergency communications, the incident command and RIC can focus solely on the situation at hand, allowing for a rapid and effective response to ensure the safety of the firefighter in distress. This practice prioritizes the immediate need for information about the location and nature of the emergency, thus facilitating a focused and efficient rescue operation.