Sick?

  Had a dreadfully sore neck yesterday, and chalked it up to somehow having slept wrong.  Today the neck is slightly less sore, but my whole body aches, and I feel like I have a low-grade fever.  Am I sick?  Or am I just sore from all the bicycling I did two days ago?  Is the sore neck microbe-driven, or pillow-driven, or perhaps road-vibration-driven?  I always find it remarkably difficult to tell when I am sick and when I'm not; even when I get a runny nose, it's as likely to be allergies as anything.  All part of life's rich tapestry no doubt.  In any case, the prescription is roughly the same: lots of water and an early bedtime...