Fevers are part of being sick. Most people have a normal body temperature of 98.6 F (37 C), Except for very young children, you are not medically considered to have a temperature until it reaches 100.4 F (38.0 C).
When you get a viral or bacterial infection, your body fights it by raising your body temperature. Your immune system works more efficiently at higher temperatures, and viruses and bacteria are sensitive to temperature.
Let your immune system work. If your fever reaches 104F (40C) or a child under three months has a temperature of 100.4, you should seen by a doctor.