I am a 36 year old female and had a bad fever. I went to the doctor and had a kidney infection, UTI, and constipation with painful gas. I had a ferocious fever Wednesday until 11pm and then the high fever broke. I have been sweating the last few nights and of coarse still have back pain and some abdominal pain. Finally this morning I started getting fever blisters and they haven t stopped multiplying. They are all around my lips and on my chin now! Ouch. The doctor prescribed me some herpes medicine and I took some Tylenol. But why so many fever blisters?