If a 13-year-old child’s body temperature reaches 37.6℃ under normal and quiet conditions, it belongs to low fever, which is abnormal and may be caused by certain diseases; mental tension, strenuous exercise, and elevated external temperature can also lead to a slight increase in body temperature, which is a normal phenomenon. Children’s low fever refers to 37.3 ~ 38 ℃, quiet body temperature is generally below 37.3 ℃, the phenomenon of elevated may be viruses, bacteria, mycoplasma, parasitic infections caused by fever, or some systemic diseases, such as blood diseases, connective tissue diseases, endocrine diseases, skin diseases, autonomic disorders, etc., need to consult a doctor in time, under the guidance of the doctor for treatment. If the child is in a state of mental stress, or after strenuous exercise, there can also be a physiological increase in body temperature, after the state of stability can return to normal. Therefore, when children have an elevated body temperature, they need to actively consult a doctor and follow the doctor’s instructions for reasonable treatment.