Temperature Regulator Error?

After a weekend of wildly fluctuating temperatures with no apparent end in sight, I'm wondering if Byron's system is having trouble regulating his internal temperature.  He does not appear sick, is as happy as ever and full of energy.  But the right lymph node is huge and hard, there is a slight ridge near the lower part of his incision and his temperature is all over the map  -  from normal to 101 to 99.3.  Tylenol seems to reduce it a bit but not enough.  I will call the surgeon on Monday just to check in. But I wonder if this is a temporary normal?