If the baby has fever at night and fever subsides in the morning, it is caused by an infectious disease in the body. It is recommended to check and treat for the pathogen, anti-inflammatory and anti-viral drugs can be used, it is recommended to choose broad-spectrum antibiotics, such as erythromycin and amoxicillin, or anti-viral drugs can also be used at the same time, for example, you can choose ribavirin granules. If high fever at night occurs during the treatment period, it is also important to consider the use of antipyretic medications, if appropriate, or the use of physical hypothermia to reduce heat treatment, which can bring relief to the symptoms of fever at night. In addition, when suffering from mycoplasma infection, afternoon or evening fever may occur. It is necessary to use anti-inflammatory drugs of macrolides continuously for about 3-5 days in order to get relief, and you can go to the hospital for mycoplasma antibody tests to make a clear diagnosis.