Can fever be beneficial? The author suggests that, under certain circumstances, it can be. For example, he writes, "many micro-organisms are killed by elevations in temperatures corresponding to moderate fevers," and there may be indirect effects on immune response such as, perhaps, increased susceptibility of lysosomes to breakage and improvement in the ability of granulocytes to kill engulfed microorganisms. In any case, he contends, this is an area that needs more study.
Whether or not you agree with the implications drawn from the data presented, this is an interesting summary of a number of studies on fever. There also are extensive references for those interested in pursuing the subject further.