This qualitative study explored the cues that nurses use to determine when a patient's clinical condition is worsening, with specific attention to factors influencing nurses' decisions to obtain assistance from the rapid response team or call a "code blue." Rather than relying on specific vital sign abnormalities, nurses relied on a combination of clinical findings (such as altered mental status), help from other experienced nurses, and their prior knowledge of the patient's baseline condition to determine when urgent physician assessment was needed. The study reveals the importance of a positive safety culture in ensuring that frontline staff feel empowered to enlist additional help when necessary.