My kids spike a fever very quickly when it's an ear infection. I'll take it twice in an hour and it'll be much higher. Ear infections also hurt more when lying down- sleeping, nursing/bottle, even playing. Keep a close eye on that. If my baby is fine while playing and eating but fussy in her crib, I know it's generally teething. Also, Tylenol should bring the fever down, teething fever will almost go away, but ear infection fever will still be fairly high. If you're in doubt, call your dr! I always felt better bringing them in for nothing than I would have sitting and wondering.