What does a "Mayday" signal indicate?

A "Mayday" signal specifically indicates that a firefighter is in distress and requires immediate assistance. This term is universally recognized in emergency services, especially in firefighting and rescue operations, to denote a critical situation where a personnel's life is at risk. When a firefighter transmits a "Mayday," it signifies the urgency of their predicament, prompting an immediate response from their team and command structure to ensure their safety.

In contrast, the other choices do not convey the same level of urgency or specific need for immediate rescue that a "Mayday" represents. A request for additional equipment, a call for backup personnel, or reporting an injury may be important communications but lack the critical nature denoted by a "Mayday" situation, which prioritizes the safety and life of an endangered firefighter. Understanding the gravity of a "Mayday" signal is crucial for effective response and rescue operations in fire service.