Definition of Fever

• Rectal temperature above 100.4°F (38.0°C).
• Oral temperature above 99.5°F (37.5°C).
• Axillary (armpit) temperature above 99.0°F (37.2°C).
• Pacifier temperature above 100°F (37.8°C). New digital electronic ones are accurate.
• Ear (tympanic) temperature above 100.4°F (38.0° C). (Note: Not reliable for under 6 months old.)
• Temporal artery (TA) temperature above 100.4° F (38.0° C) (Note: more reliable than tympanic thermometers, but not to be used for children under 6 months old)