Teething Part 2 What causes fever during teething? 1. Pain from d erupting teeth could be responsible for fever during teething periods.2. Weak immune system, when teeth is abt to erupt, there will be weakened immune system for d said period especially with first set of teeth, which makes d baby go down with common sickness often than normal e.g cough, malaria, catarrh.3. Infection- this is mostly caused by putting unhygienic things from the floor into their mouth in order to soothe their gums, this can also cause diarrhea.Incase ur baby has any of any d following signs, see ur doc, he will treat ur baby according to d symptoms he's presenting with.