I don t know, I have COPD, and just after retiring with my oxygen and CPAP, I started shivering, I covered up but that didn t seem to help, I finally got up and now have a heating pad and blanket on me and am still shaking...I had an excessive amount of coughing last night, but seemed to be doing better today until this hit.My muscles seem very tight thru my shoulders. I also sent to feel movement in my head..Should I be concerned?