To be the one guy, but as a teenager, I did once collapse from a fever, so I know it can happen. I don't know that manga authors have seen or experienced it, but it matches up with the cliche. I felt crappy but functional, overexerted myself, and collapsed. I had to be helped back to the car, and when I got home, I slept for an hour, after which I felt good enough to walk around again. The fever broke the next day.