A fever is an increase in normal body temperature. An average body temperature is typically around 98.6 degrees Fahrenheit (37 degrees Celsius). It's usually a symptom of an infection or illness ...

Both viral and bacterial infections can result in fever, but the onset, severity, signs, and management are different.

But it remained unclear whether fever’s tie to specialized adaptive ... about 5 degrees above their typical temperature, for five days. Compared with sick fish kept at their usual temperature ...