Patient: I suddenly feel really cold to a point where i am shivering and my teeth are chattering.This only happens at night and is not really to do with the weather. It starts off with a reaaly bad headach where i can feel my brains pumping. When i move my head i feel my brain moving. Please tel me the cause of this or if its symptoms of underlaying illness. I get really scared when this happens and it takes about 4-5 hours for my body to go back to normal. The thing is my body is normal temp, but my feet is slightly cold, but i feel soo cold as if i am in a bucket of ice. Please help me.