I used to take a long time to go to sleep or wake up shortly after falling asleep. I had read on Dr. Mercola's site that the lowering of body temperature acts to put us to sleep, so my hypothyroid, too-low temperature didn't allow more lowering. I guess I was wide awake to preserve life when my temp was 95.9 - 97.2F. (In cold survival situations people who fall asleep die.)
I have had some 1,2 and even 3 hot bath nights to get back to sleep. I used to monitor my temperature frequently at night. Now I just take a hot water bottle to bed. I go right to sleep and sleep all night long. Electric heating pads are not recommended. They put off harmful EMF, ElectroMagnetic Fields, plus I got a fatty tumor where I fell asleep on one set on low. Sweet dreams!