Colds with low fever that does not go away may be caused by factors that have not been eliminated, medications that do not cover the causative organisms, or the presence of other causes of fever, and so on. 1. The causative factor is not eliminated: colds are caused by viral infections. Common colds usually do not require antiviral drugs and can be cured on their own. Influenza requires the use of antiviral drugs such as oseltamivir. If it is not used, it will not be able to effectively control the symptoms of influenza and may lead to recurrent fever. 2. Selection of drugs does not cover the causative organisms: If the flu is secondary to bacterial infections, the drugs may not cover the causative organisms, and sputum cultures need to be completed to identify the causative organisms and to select the appropriate antibiotic treatment. 3. Fever caused by other reasons: there may be other diseases, such as hyperthyroidism, tuberculosis, which can also lead to increased body temperature; chemotherapy or radiotherapy can also cause a decrease in white blood cells, thus reducing immunity, resulting in high body temperature. If you have a cold with a low-grade fever that doesn’t go away, it is recommended that you consult a doctor in a timely manner, complete the relevant examinations, identify the cause of the illness, and follow the doctor’s instructions for treatment.