Type B influenza is a type of epidemic influenza characterized by a rapid onset, feeling feverish and chilled. Body temperature usually rises quickly within hours, reaching 39 to 40 degrees Celsius, or even higher. It is accompanied by headache, general body aches, fatigue, and reduced appetite. Its respiratory symptoms are relatively mild, including dry throat, sore throat, dry cough, and possibly diarrhea. Type B influenza is difficult to distinguish from the common cold and typically requires laboratory identification for diagnosis.