Baby teething fever :

The pain & discomfort which results from baby teething is due to the pressure exerted on the tissue in the mouth, when the teeth erupt. Gently rubbing the gums with a chilled, wet wash-cloth may give the baby some relief.

Being feverish maybe a sign of teething, but not always so. Fever may also be a symptom of something else for which you may visit your doctor. 

Teething has NOT been shown to cause a high-grade fever in babies. If your child develops fever MORE than 100 degrees, look for other signs of illness. Although fever may coincide with baby teething it is best to check with your doctor if your baby has a fever or diarrhea.