My son hit his head playing hockey. he has no headache or dizziness. he has not vomited. however he is now running a fever. is this cause for concern?

No, unrelated fever: It is highly unlikely to have a fever as a result of a head injury that was not severe enough to cause concussion like symptoms. It is more likely coincidental with a new onset infection. Depending on degree of fever and other symptoms, it could be treated symptomatically with acetaminophen or if persistent, should be evaluated.

No: Fevers are not an associated symptom of an impact to the head or concussion. If the fever is above 101.5 he should be evaluated by a physician.