Normal body temperature is a moving target: In children younger than six months of age, the daily variation is small. In children 6 months to 2 years old, the daily variation is about 1 degree. Daily variations gradually increase to 2 degrees per day by age six.
Call a doctor right away if:
- A baby less than 90 days old has a rectal temperature of 100.2°F (37.9°C) or higher.
- A baby 3 to 6 months old has a fever of 101°F (38.3°C) or higher.
- A baby 6 to 12 months old has a fever of 103°F (39.4°C) or higher.
- A child under age two years has a fever that lasts longer than 24 to 48 hours.
- A fever lasts longer than 48 to 72 hours in older children and adults.
- Anyone has a fever over 105°F (40.5°C), unless it comes down readily with treatment and the person is comfortable.
- There are other worrisome symptoms. For example, irritability, confusion, difficulty breathing, stiff neck, inability to move an arm or leg, or first-time seizure.
- There are other symptoms that suggest an illness may need to be treated, such as a sore throat, earache, or cough.
- You think you may have incorrectly dosed acetaminophen or ibuprofen.
More Information
MedlinePlus Medical Encyclopedia: Fever
Temperature measurement
Thermometer temperature
Fever and Taking Your Child's Temperature (Nemours Foundation)
Fever in Infants and Children (American Academy of Family Physicians)
Temperature-Taking Tips (Mayo Foundation for Medical Education and Research)
