What would you measure to determine if a patient is febrile?

To determine if a patient is febrile, the primary measurement taken is temperature. A fever, or febrile state, is defined as an elevation in body temperature, typically above the normal range of around 98.6°F (37°C). By measuring the temperature, healthcare professionals can identify whether the patient has a fever, which can indicate an underlying infection or other medical conditions.

While the other vital signs such as heart rate, blood pressure, and respiration rate can provide important information about a patient's overall health and can be affected by fever, they do not directly measure the presence of a fever itself. Instead, they might respond to the fever, showing increased heart rate or altered blood pressure, but only the measurement of temperature can confirm a febrile condition directly.