two days ago when i woke up, i felt dizzy. the side of my head was hurting really bad and i was really cold and shivering . but then i took advil and went to sleep and later i felt okay for a while but at night the same thing happened. although it wasnt as bad, i felt cold and my head hurt. also sometime i feel cold, hot, and normal even if the room temperature is stable. I am feeling a little better but still i want to know the cause of this sudden headache