iIhave taken ultracet/ ultram before and had the same reactions. Last night I had nothing else to take for my awful awful headache, so I had to take the ultracet. First of all it did not ease the headache at all. I woke up this morning and felt like I had the jitters, I got hot and started sweating, then I started vomiting. Now my head feels like I am in a tunnel and I have cold chills. Anything with quick movement makes my head spin and I have to vomit again! If I had not known what this medicine made me do before I would have went to the ER, but fortunatly I know just to wait it out and hopefully it will be out of my system soon.