As far as I know, nasal congestion and fever are generally regarded as symptoms of many illnesses (e.g. flu), not as mechanisms that the body uses to fight an infection. Nonetheless, a lot of people still seem to abide by the rule that you should "tough it out" and not take medicine to reduce these symptoms. Some people seem to express the belief that they will actually get through there illness faster if they suffer through it.
Is there any evidence to support that belief? It seems to me that such an argument would only be valid if one could show that the body is actually using the fever or nasal congestion to eradicate the infection. I could imagine that there might be instances like the following:
a certain type of microbe dies at a few degrees above body temperature, or the higher temperature significantly slows down reproduction
nasal congestion restricts the ability of the microbe to get to XYZ in the body, thereby limiting the effectiveness of the infection.
Are there any examples where this might be the case? Or are there some common cases in which fever or congestion can be shown to actually help fight the infection?