Yes he should reschedule the infusion!
Whenever patients who are taking any biologic agent (infused or injection) have a fever or any symptoms that could be an infection, we would advise against receiving any infusion until the symptoms have completely cleared. If someone is taking an injectable medication (such as Enbrel, Humira, or Kineret) we advise to hold the medication until the symptoms resolve.
We have a very low threshold in our practice for infection, and always ask patients to speak with their rheumatologist or primary care provider whenever there is a question concerning infection. It is better to err on the side of caution by holding a medication if there is a question, than to risk the development of making a “mild” infection turn severe!