BackgroundEarly identification of clinical deterioration in the prehospital setting is essential for optimizing patient outcomes and minimizing preventable adverse events. Emergency Medical Services (EMS) clinicians operate in time-sensitive, resource-limited environments, where structured assessment tools provide valuable objective support. ObjectiveTo outline key clinical red flags in prehospital emergency care and evaluate the contribution of standardized scales—National Early Warning Score 2 (NEWS2), Glasgow Coma Scale (GCS), Visual Analog Scale (VAS) for pain, and Patrick (FABER) test—to early risk detection, care escalation, and handover communication. MethodsNarrative review synthesizing clinical evidence, validation studies, and guidelines relevant to EMS practice. Literature was sourced from PubMed, Scopus, and key EMS resources, prioritizing prehospital applications of these tools. ResultsCritical red flags include NEWS2 scores ≥5 (acute deterioration) or ≥7 (high risk of adverse outcomes), GCS ≤13 or decline ≥2 points, severe pain (VAS ≥7) or persistent uncontrolled pain, and positive FABER findings with functional limitation. Serial reassessment and documentation improve situational awareness and care continuity. ConclusionRoutine integration of validated clinical scales into EMS protocols enhances early recognition of red flags, supports evidence-based decision-making, and improves patient safety. Alignment with current guidelines, such as those from NASEMSO, should be prioritized.