What initial assessments should I perform for an adult presenting with fever to determine the underlying cause?

Initial assessments for an adult presenting with fever to determine the underlying cause include:

• Measure vital signs: temperature, heart rate, respiratory rate, blood pressure, oxygen saturation, and assess level of consciousness to identify severity and possible sepsis.
• Examine for signs of sepsis or serious infection such as mottled or ashen appearance, cyanosis of skin, lips or tongue, non-blanching petechial or purpuric rash, breaches in skin integrity, or other rashes indicating infection.
• Ask about recent fever or rigors and urinary output in the past 18 hours to assess systemic involvement and hydration status.
• Consider the possibility of meningococcal disease or bacterial meningitis if there are signs such as non-blanching rash, neck stiffness, or altered consciousness, referring to specific NICE guidelines on these conditions.

These assessments help identify the underlying cause of fever and the presence of any life-threatening infections requiring urgent management ².