Fever Definition and Assessment in Infants

Definition and Measurement

• The American Academy of Pediatrics defines fever in infants as a rectal temperature of 38.0°C (100.4°F) or higher, according to clinical guidelines 1, 2
• A temperature of 98.4°F (36.9°C) is not considered a fever in infants, as it falls below the defined threshold of 38.0°C (100.4°F) 2

Risk Assessment and Clinical Significance

• Infants younger than 3 months with temperatures ≥38.0°C (≥100.4°F) are considered at higher risk for serious bacterial infections 2
• Recent antipyretic use may mask a true fever, highlighting the importance of accurate temperature assessment and medical history 2