“Cold” usually refers to acute upper respiratory tract infections, 4-year-old baby fever of 37.5 ℃, cough and runny nose can be seen in the disease, but at the same time need to pay attention to identify bronchopneumonia and other diseases. “Cold” usually refers to acute upper respiratory tract infection, is a common acute infectious diseases in children, most of the viral infections, such as rhinovirus, influenza virus, etc., part of the combination of bacterial infections, for children 4 years old, can be manifested as a rise in body temperature to 37.5 ℃, coughing and runny nose, and other symptoms, usually less severe symptoms. But at the same time need to pay attention to identify other diseases, such as bronchopneumonia, the disease will appear obvious cough, and present progressive aggravation, may be accompanied by wheezing, fever may present low fever or obvious high fever, the progress of the disease may be obvious aggravation of the lung lesions, serious cases may appear respiratory distress and heart failure, etc., need to actively consult the doctor for treatment. It is recommended to actively seek medical treatment and be evaluated and judged by a specialist.