Your child has a fever if:

• Rectal, Ear or Temporal Artery (TA) temperature: 100.4° F (38.0° C) or higher
• Oral or Pacifier temperature:  100° F (37.8° C) or higher
• Under the arm (Axillary or armpit) temperature:  99° F (37.2° C) or higher
• Limitation: Ear (Tympanic Membrane) temperatures are not reliable before 6 months of age
• Temporal artery and skin infrared temperatures may be reliable in young infants (new research)
• Use this guideline if fever is your child's only symptom

Causes

• Main cause: colds and other viral infections
• Fever may be the only symptom for the first 24 hours (i.e., viral fevers). The onset of symptoms (runny nose, cough, diarrhea, etc.) are often delayed. In the case of Roseola, fever may be the only symptom for 2 or 3 days.
• The cause of the fever usually can't be determined until other symptoms develop. That may take 24 hours.
• Bacterial infections (e.g.,  Strep throat or urinary tract infections) also cause fever
• Teething does not cause fever

Fever and Crying

• Fever on its own shouldn’t cause much crying
• Frequent crying in a child with fever is caused by pain until proven otherwise
• Possible hidden causes are ear infections, urinary tract infections, sore throats and meningitis.

Normal Variation of Temperature

• Rectal: A reading of 98.6° F (37° C) is just the average rectal temperature. It normally can change from 96.8° F (36° C) in the morning to a high of 100.3° F (37.9° C) in the late afternoon.
• Oral: A reading of 97.6° F (36.5° C) is just the average oral temperature. It normally can change from a low of 95.8° F (35.5° C) in the morning to a high of 99.9° F (37.7° C) in the late afternoon.

Return to School

• Your child can return to child care or school after the fever is gone and your child feels well enough to participate in normal activities.