My son has a fever of 102 with no other symptoms. The fever is not responding to medicine. What should I do?

Fever. . Fever that doesnot respond to tylenol (acetaminophen), (acetaminophen) either the dose of tylenol (acetaminophen) is not accurate or it may indicate a more serious problem, especially if there is rash or respiratory problem or lethargy.
See PCP ASAP. With that high fever your son needs to be evaluated to find the underlying reason of fever.