In most cases, no—but we need to qualify this: A fever is usually an indication of a bacterial or viral infection. While debate about whether fevers actually speed up the body’s inflammatory response to infection is ongoing, no clinical evidence is apparent that reducing fevers by taking medication that quells the fever actually slows the healing process. But for most doctors, fevers are considered an important part of the body’s defense against infection, especially because most viruses and bacteria that cause disease thrive best at our body’s normal temperature—98.6°F. Thus, a fever means the body is fighting off the pathogens and is actually helping you. A fever for an adult, for example, is usually considered to be above 99 to 99.5°F (37.2–37.5°C)—but all higher temperature fevers should be checked out by a physician.