Fever is the medical term used to describe a temporary rise in body temperature, usually as a response to infection. It is a common symptom that signals the body is fighting off harmful microorganisms such as bacteria or viruses. Normally, human body temperature is around 37°C (98.6°F), but during a fever, it can climb higher, sometimes reaching dangerous levels if not managed properly.

Fever itself is not a disease, but rather a sign that the immune system is actively working to protect the body. While mild fevers can often be managed at home, very high or persistent fevers may require medical attention, especially in young children, the elderly, or people with weakened immune systems. Monitoring body temperature and understanding when to seek help is important for overall health and safety.