50 year old male, take colesterol meds and vitamins. On occasion i experience cold chills to the point that a physically shake and teeth chatter. No fever with the chills. can last a few hours. My wife will take a heating pad and place on high in the bed for me to lie on and then cover me with several blankets. At this point it will take a few hours to get over the chills. personal physician does not know what this could be.