Apr 01, 2015 · Fever means a body temperature of 100.4° F (38°C) or higher. An infection, such as the flu, is the most common cause of fever. Other conditions can also cause a fever. These include diseases that produce inflammation, such as rheumatoid arthritis, reactions to drugs or vaccines, and even certain types of cancers. Fever symptoms.
Jun 20, 2016 · How and when you should treat a fever is generally determined by your age. If left untreated, fever can lead to serious complications in young children, older Author: Corey Whelan.