Hello, If symptoms do not indicate a respiratory infection or develop into a cold with all the expected side effects, look into some systemic disorders. A fever for a long period of time is a concern and indicates the body is fighting an infection. Blood tests will provide a great deal of information about overall health. Mononucleosis and blood disorders are a couple of possibilities. Consider having a dental exam to rule out any oral infections. This includes an abscessed tooth or periodontal disease. An oral infection, untreated, can spread and cause a systemic reaction including sepsis. Try to control the fever with Antiinflammitory medication, keep well hydrated and make sure to have a balanced diet to avoid vitamins deficiencies. Thank you for your inquiry. I hope that my suggestions are helpful.