Children with fever 37.5 ℃, nasal congestion may be related to acute upper respiratory tract infection, measles, sinusitis and so on. 1. Acute upper respiratory tract infection: mostly caused by rhinovirus, influenza virus and other infections, the onset of disease is more acute. Mainly manifested as nasal symptoms, such as nasal congestion, sneezing, etc., and severe cases may have fever. 2. Measles: mostly due to measles virus infection, in the pre-morbidity period, there may be low-grade fever, accompanied by nasal congestion, coughing and sneezing. 3. sinusitis: mostly due to bacterial, fungal or viral infections caused by pathogenic bacteria invasion of the body caused by increased nasal mucosal secretions, nasal congestion, sneezing and other symptoms, but also accompanied by symptoms of fever. Children with a fever of 37.5 ℃, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.