What term is used to describe emergency response that utilizes lights and sirens for life-threatening events?

The term used to describe emergency response that utilizes lights and sirens for life-threatening events is "Code 3." This classification is commonly recognized in emergency services to indicate urgent situations where immediate response is necessary to protect lives. The activation of lights and sirens signifies that the responding unit needs to navigate through traffic and reach the scene as quickly and safely as possible, alerting other road users to yield.

In contrast, "Code 1," "Code 2," and "Code 4" pertain to different levels of urgency. Code 1 usually indicates a non-emergency situation, Code 2 marks a response without lights and sirens but is still urgent, and Code 4 generally represents a situation that requires no immediate response. This hierarchy of codes helps prioritize response efforts and ensures that emergency services can effectively manage both life-threatening and lesser emergencies.