The average person's body temperature is 98.6 °F (37 °C). Any temperature exceeding this is regarded as a fever. Fevers are frequently an indication that your body is battling a bacterial or viral infection. Any fever that is brought on by an underlying viral infection is considered a viral fever. Humans are susceptible to a wide range of viral illnesses, including the flu and the common cold. Many viral infections present with a low-grade fever as a symptom. However, some viral illnesses, including dengue fever, can raise fever levels.