Normally there is no co-relation between deworming and fever. The regular deworming medicine is ALBENDAZOLE, which is not absorbed from intestines into blood. It kills the worms in the intestines and excreted unabsorbed in stool.
Fever would be because of some other reason like gastroenteritis, where there is fever with abdominal pain. It is to be decided whether it is viral or bacillary. Treatment is likewise.