Final answer:
The EMT should be most concerned when a child presents with fever and ear pain.
Step-by-step explanation:
When a child presents with fever and ear pain, the EMT should be most concerned. While fever can be a common symptom of various illnesses, ear pain can indicate a more serious condition such as otitis media, which is an infection of the middle ear. In children, otitis media is a common cause of fever and ear pain.