Which term is described as the initial evaluation typically performed by the first arriving unit?

• A. Fire Suppression
• B. Size Up
• C. Fog Stream
• D. 3 Types of Attack

Answer: (B)

Size up is the rapid, initial evaluation the first arriving unit performs to understand the scene and set priorities. It involves quickly observing the building and fire conditions, locating the fire and its likely path, assessing occupant safety and potential entrapment, identifying hazards (like collapse potential or exposures), and noting available resources and water supply. This concise assessment guides the immediate actions: deciding whether to pursue an interior attack or take a defensive stance, whether to prioritize rescue or evacuation, and what tactics and resources will be required. It also informs safety decisions and what to communicate to the incident commander. Fire suppression, fog stream, and the concept of attack types are actions or tactics, not the initial evaluation itself.