Fever is a symptom in the Standard Plagues, the Simian Flu DLC & the Necroa Virus DLC. It increases body temperature, contagiousness, and severe dehydration through excessive sweating. It slightly increases disease lethality and Infectivity, although it is more lethal than Paralysis.
- Along with Diarrhoea, Tumours and Inflammation, Fever is one of four symptoms which can be better understood by scientists during a game, making a plague easier to cure when it is evolved or mutated.
- In Necroa Virus, Fever, along with Coma, weren't lethal. They do have other effects. In Necroa Virus, while Coma reduces infectivity, Fever slows research speed.
- In Black Death and Smallpox, it is evolved from the start.