How long has your child had a fever?
Any trouble breathing?
Is your child still drinking liquids and making at least one void every 8 hours?
Does the fever respond to Tylenol or ibuprofen (Advil or Motrin)?
Was your child exposed to someone with similar illness?
I notice you've gone offline, so I'll leave my thoughts.
Fever is usually defined as a temperature above 100.4 degrees Fahrenheit or 38 degrees Celsius. Regarding infection, fever is actually a protective mechanism--that is, the body is trying to make itself an unsuitable environment for the infection. I would advise evaluation by a doctor if: the fever occurred after exposure to a serious illness (e.g., meningitis); the fever has persisted beyond 48 hours; the fever does not respond to fever medications; your child is having difficulty drinking or holding down liquids; your child is not making at least one void every 8 hours; the fever is associated with other focal symptoms (e.g., trouble breathing; severe headache or sore throat; skin rash; pain at ears or abdomen, with urination, etc.; changes in alertness/consciousness or ability to move/sense/speak); the fever reaches 105 degrees Fahrenheit (not dangerous, but merits medical evaluation).
If the temperature lingers above 102 degrees Fahrenheit (a moderate fever) despite fever medicine, you might consider a 5-10 minute lukewarm bath or shower with rapid towel drying afterward to gently lower temperature. Do not use alcohol baths or anything that would cause a chill as this might make the fever spike higher.
If the fever cause is a virus, one's immune system will do its job and usually clear such an infection within 1-3 weeks. Antibiotics only work against bacteria, not viruses.