What should I do if my child has a fever?

Pediatricians consider a fever significant when it's above 100.4 degrees. Call your pediatrician if your child (1) is younger than 4 months and has a fever; (2) has other symptoms along with the fever; (3) is a toddler who has had a fever for more than three days or is an older child with a fever for six days. In other cases, it's usually safe to use children's ibuprofen or acetaminophen. Never give a child aspirin – it poses a risk of Reye's syndrome, a rare but serious illness that affects the liver and brain.