A fever of 38℃ is a low fever, but whether the condition is serious or not is not judged by temperature alone, but also by a comprehensive analysis of other symptoms, signs and test results. If an adult has a fever of 38℃ and no other accompanying symptoms, the condition is generally not serious and can be treated symptomatically by drinking more water and physically cooling the temperature. If the blood test suggests a bacterial infection, antibiotics can be added. Usually a complete recovery can be achieved in about a week. Infants and toddlers with fever up to 38℃ are not serious because their thermoregulatory mechanism is not yet well developed. When the body is invaded by minor bacterial and viral infections, the body temperature will rise more rapidly, so you can give physical cooling, drink more water and measure the body temperature regularly. If the temperature continues to rise, it is important to seek medical attention to prevent the condition from worsening. The condition is more serious if it is accompanied by phlegm, dizziness and headache, chest pain, difficulty in breathing as well as abdominal pain and diarrhea, or if the fever persists. In addition, some non-infectious factors can cause fever, such as tumors, blood system diseases, rheumatic immune diseases, etc., which are more serious conditions. Therefore, whether a fever of 38℃ is serious or not depends on the specifics of the disease. Once a fever occurs, it is important to actively look for the cause of the disease and treat it accordingly.