What should be the first step after arriving at an emergency scene?

Conducting a scene size-up to assess the situation is essential as it allows responders to gather crucial information about the emergency. This step involves evaluating the safety of the scene, identifying hazards, determining the nature of the incident, and understanding the resources needed to manage the situation effectively. A thorough size-up helps in making informed decisions about what actions to take next, such as whether additional support is necessary or if immediate firefighting operations should begin. By assessing the environment and potential risks, firefighters can better strategize their approach while ensuring the safety of everyone involved.