Fever is a medical indication that explains an increase in inner body temperature to levels higher than the normal. In general fever is a warning of something abnormal in the body. It is the body's reaction to a sickness. In case of adults, a fever typically is not risky except it reaches 103 F (39.4 C) or higher. But in case of young kids and infants, a little increase in temperature may be a warning of some serious infection.
Fever is mainly defined as increase in temperature 1° or more above the normal (98.6 degrees Fahrenheit or 37 degrees Celsius is normal body temperature). Mild or temporary increases in body temperature are normal with slight infections. Fever is an indication of an illness or infection. It is not a disease. Fever helps the body to fight against infections by building the body's resistance systems work more powerfully. Bacteria and viruses cannot survive at elevated temperatures and are destroyed by fever. Fever could play a key role in helping the body to fight off many infections.
The symptom of fever depends on what is causing it. In some cases fever can cause a chill. This chill happens when the brain increases the body's "thermostat," the body reacts by shivering to increase the temperature. Shivering creates warmth in the body. Once the temperature rise, the person frequently feels warm and when the fever goes away, the sufferer may start to sweat.
The main danger of mild fevers is dehydration. When someone has a fever, they require more fluids than normal. A fever higher than 106 degrees Fahrenheit can affect brain and result brain damage and perhaps death. Fevers higher than 106 degrees are very unusual.