low temperature

[crmnj]

Nearly every night between 12:30 and 3am I wake up freezing. Room temperature is 66-68. My temperature usually drops below 95, often to 92 or 91.6. I put on a sweat suit and wool hat and can usually get back to sleep. A dual-control electric blanket helps somewhat but not entirely. My blood sugar is normal at that time, but blood pressure is high (for me--150/80). I have talked to 5 doctors about this (2 different endocrinologists), had scads of blood tests (thyroid is okay), and lately had MRI to check hypothalamus--also OK. My doctors say my meds aren't the cause. This began about 3 months ago. If I take an afternoon nap, it sometimes happens then, too.
I am 77 and in fairly good health, ride my bike several times a week, and  my main problem is polymyalgia rheumatica.  Does anyone have any ideas?  The last endocrinologist said I was a puzzle to him, and he later wrote my family doctor a three-page letter about me.  

[Braintoobig]

Also when you had your thyroid checked, did they just run a TSH level on you or did they actually test the T3 and T4 thyroid hormones in the blood? Sometimes a normal TSH level isn't enough to diagnose a thyroid issue.

Another thing to think about is wearing a halter monitor to see what's happening with your heart while you sleep. I would even consider a sleep study ordered by a neurologist since this seems to only be happening while you sleep.

[Braintoobig]

This is probably a stupid thing to say but have you tried different thermometers just in case yours isn't calibrated properly?
Just another thought to throw out there....