Undiagnosed on-going daily/high temperatures

Good day,
I would like to hear from patients and doctors on this forum who can hypothesize as to the possible cause of on-going, daily temperatures ranging from 99.0 - 99.9 F on a daily basis. The median is 99.5 F. I range from feeling cool to very hot (as in a sauna) with perspiration.

None of the doctors (gastro, internist, neurologist) can find a cause.

The onset of these temperatures occurred right after severe constipation. My upper endoscopy was unremarkable (thank goodness). I also have chronic vestibular migraines.

thank you,

Kathryn