When I urinate, it is warm although I took antibiotics for a urinary tract infection. Why?

Patient: When I urinate, it is a little warm. A couple weeks ago I had anal sex and the next morning a warming sensation started. A few days later I went to see a doctor and I was prescribed an anti-biotic (ciprofloxacin) for 5 days, which I assume is for a urinary tract infection. They were 5 large white pills. I finished the anti-biotic and it is now a week later and the warming sensation still is there. Im just wondering what this is? I’m worried that it is very serious, although I know the girl does not have any STD’s.

Doctor: