a fever is very non-specific -- there can be many things causing his fever but if he has an ear infection this is the most likely culprit. most ear infections are preceded by a cold so even colds can cause fevers of this magnitude but unfortunately i do not know enough about your child or his particular case to know if "something else" is going on. don't let a fever frighten you. children can get some pretty impressive fevers. medical providers rarely get excited with fevers under 105f in a one-year-old. children tend to get higher fevers because their immune system is not very good (the fever helps fight infection) and their "cooling system" is not very efficient (we cool by sweating over a large skin surface area so the smaller the body the less cooling). most fevers should improve on day three or four of the illness but if it does not or if you child is experiencing any other worrisome symptoms you will need to have him re-examined.
could my 1-year-old's ear infection cause a high fever (103f)?