When a baby has a fever of 38.5℃ that does not go away, first of all, the primary disease as well as the site and severity of the infection should be clarified. In this process, the temperature should be taken and recorded every 2-3 hours to observe the changes in temperature and see the occurrence, development and passage of the disease. In addition, it is important to observe the accompanying symptoms of the baby, such as whether the fever is accompanied by coughing, wheezing, and runny nose, and whether the fever is accompanied by frequent, urgent, and painful urination, and whether the fever is accompanied by vomiting and diarrhea, etc. This will provide clues for the diagnosis. Babies can use physical methods to reduce heat treatment during the fever, such as drinking more water, keeping neck clothes from piling up, keeping the neck bare, and increasing heat dissipation. In addition, you can give your baby a hot bath and treat the body temperature above 38.5°C with antipyretic drugs, including acetaminophen, ibuprofen, antipyretic suppositories, etc. If the fever persists high and does not subside you should go to the hospital for active diagnosis and treatment