I believe its being caused by some back or neck pains... but... I am literally shivering under 3 thick blankets, so damn cold... unless I take like 3 advil I am not able to get out of the blankets! As soon as I take the advil I start sweating incrediably bad... so then I can function out side of the blankets. This has been going on for 3 days now and my girlfriends been taking care of me a little so its ok I guess it just sucks. I've been drinking tons of hot chocolate which warms me up and tastes yummy... but man this is getting old.