Fever is not by itself an illness but usually a symptom of an underlying condition, most often an infection. It is also known as a high fever or a high temperature
It is usually associated with physical discomfort, and most people feel better when a fever is treated. Depending on your age, physical condition, and the underlying cause of your fever, you may or may not require medical treatment for the fever alone.
Many experts believe that fever is a natural bodily defense against infection. Non-infectious causes of fever can also be found
It is generally not considered dangerous, but hyperthermia can cause dangerous rises in body temperature. This can be due to an extreme temperature associated with heat injury such as heat stroke, side effects of certain medications or illicit drugs, and stroke. With hyperthermia, the body is no longer able to control body temperature.