I recovered with antibiotics from a bad chest congestion 2 weeks ago. After that I am weak but ok until 3-4 pm. After that time I have the symptoms of a light fever , and I like going to bed. My actual temp is around 36.2C in the morning (that s normal for me), and rises to 37C in the afternoon. Also my thermoregulation is bad, if I go out well covered in the morning cold (20F to 40F) I don t feel particularly cold, but my temp drops from the low 36C to under 35C. My doctor checked my thyroid , results are normal. I am 75, male, I was fine before my bad chest congestion.