re: Calling all doctors....advice needed

Generally your temperature can raise and lower depending on the day, time of day, and level of certain things in your body. When a woman is ovulating for example, their temperature raises a full degree.

However, 99.6, as Scruff pointed out isn't really a fever because it can be considered physiological at times. Meaning your body can do it just because.

100.4 is considered a fever because it is more likely something is causing that fever through inflammatory mediators like TNF, IFN, and a couple others.

That generally means an immune response to a pathogen, however it can be from just an overproduction of those by an auto-immune process. A couple other things can cause fever, and different diseases or processes can produce different degrees of fever.