I had another one a few nights ago. They are somewhat common. I have probably had three in a week before, typically when I am training hard. What happens is I go to sleep in the 64-65F apartment (winter indoor temperature) under a sheet, fleece blanket and thin down comforter and I am cold when I get in bed but inevitably wake up in the middle of the night roasting. It is more common when I am not hydrated enough, in addition to the hard training, but I typically wake up in the morning feeling very rested and a comfortable temperature.
My theory is that my body in a nine hour attempt to recover goes into white blood cell, or rebuilding, overload and churns through energy in an attempt to repair itself. If you ask me at 1 am how I feel during a mini fever, fever would be a decent description, but if you ask me at 6 am I will say I slept like a rock.
I have no scientific basis or evidence to back this up. It is more or less unpredictable although increasing the physical stress in my training or being dehydrated seems to be the only times I wake up in the night to notice it.
Have you ever had a mini fever?