I had a fever between 103-104 almost 3 days ago,I shook so hard It hurt my chest, back and calf muscles,I went to bed and had my grandson place several quilts on top of me,I was out of Tylenol .i better today,my fever came down by 3am,but I wasn t able to get out of bed for 2 days except to the bathroom,today I have been up in a chair,just feel weak if I get up for to long.i had a endoscopy and colonoscopy,because I had seen some blood and was concern because I had an esophageal bleed a yr ago.i was just wondering what could cause that to come on so sudden.Thank you