Can influenza A or influenza B cause high fever?

Influenza A or influenza B does not necessarily cause high fever. Influenza A is an acute infectious disease whose main symptoms include fever, headache, general fatigue, and sore throat; however, it does not always result in high fever—some patients may only experience low-grade or moderate fever. Influenza B is an acute respiratory infectious disease with primary symptoms such as fever, cough, headache, muscle aches, fatigue, and sore throat. Similarly, high fever is not always present, and patients may exhibit only low or moderate fever.