What Causes Sudden Feeling Of Hot Sensations On Back?

My back heats up out of the blue. It gets hot like a heating pad. It is even hot to the touch. I initially thought this was tied to my menopause, but those symptoms have gone away, but my back still heats up sometimes once a day, other times multiple times. But night is the worst, it will wake me from a sound sleep, then once it passes I then am cold and have been awake long enough that I can t get back to sleep. I was told it was because of my thyroid, then 3 mos later was told my thyroid is not hyper enough to cause this. I don t know what to do, but it is getting intolerable.