Although the evidence is only indirect, fever is believed to enhance the body's immune response. The increased temperature may actually impair the replication of infecting bacteria and viruses that are adapted to survive best at your normal homeostatic body temperature range. Hope this helps.
Recall the endosymbiosis hypothesis and recall endosymbiosis. Remember that the very first cell was a prokaryotic cell. Which engulfed chloroplast precursors and mitochondria. We all come from these cells. And how we evolved over time shows the relationship. I'm a bio major hope I helped