Which of the following would NOT be classified as a sign?

In medical terminology, a "sign" is an objective indication of a condition that can be observed or measured by someone other than the individual experiencing it. Signs are typically physical findings that a first responder or healthcare provider can detect during an examination.

A headache, on the other hand, is a subjective experience that cannot be directly observed or measured by an outsider; it is reported by the patient as a symptom of their condition. This makes it distinct from the other options, which are observable indicators of a medical issue. Pallor, shortness of breath, and chest pain can all be recognized and assessed by a responder, making them signs of potential underlying health concerns. Hence, the presence of a headache as a self-reported sensation prevents it from being classified in the same category.

Understanding the difference between signs and symptoms is crucial for effective assessment and communication in emergency situations.