hot burning feet

Ever since I was a young girl, I have always had hot burning flamation from heel to toe on the bottoms of my feet, I sleep with cover off my feet even on the coldest of nights, and several times during the night I rub cool cream to relieve the burning. Some nights I would have difficult time to sleep, as my right or left feet would twitch furthermore, pain would shoot from the shin up to lower back three, or five consectitive nights. I want to know what is causing this. I have seen doctors who do not know what to make of it.