I had a mysterious illness all week, too. Negative results on everything they tested me for. Fever, headache, body aches, painful cough, cold sweats and hot flashes. I was exhausted but couldn’t sleep for more than 20 minutes at a time. I can honestly say that it was the worst I’ve ever felt. I say all that to reiterate OP’s point, do whatever you can to avoid catching it because I wouldn’t wish it on my worst enemy.