I have night sweats at times, and it's strange because I don't sweat much at all the rest of the time, I can easily go without deodourant even in warm weather. But when I'm ill I sweat at night if I have a fever. Last year I had an infection, I was in hospital at the time and my temperature got to 40 degrees C. The night my fever broke I sweated so much the nurses had to change my sheets about four or five times. This happens in a much more minor way quite often when I'm a bit feverish. It's a side effect of steroids for me too.