An evaluation of a fever in an adult begins with a medical history and physical examination.

Options for measuring the temperature include:

• Oral thermometer:
• Reliable and easy to obtain
• Rectal temperature:
• Very reliable, but more difficult to obtain
• Best option for infants and young children
• Under the arm temperatures:
• Unreliable results
• Thermometer ear probe:
• Unreliable results
• Thermometer skin patches:
• Unreliable results

The need for additional tests is determined by the severity of the fever and the presence of other symptoms.