For About A Week And A Half, Or Even Two

For about a week and a half, or even two weeks, each evening I was getting very, very cold all over with my hands and nose icy feeling. Went to be very bundled up and woke each morning having sweat through everything. I also had thick greenish phlegm and coughed a lot. I slept a lot for 2 weeks. Now I am feeling better but not perfect; some congestion and tiredness still. Were these symptoms those of a virus or could they be the symptoms of a serious illness?