If the body temperature of an eight-year-old child is 37.5 ℃, it is not normal and belongs to the situation of fever, because the child’s body temperature exceeds the axillary 37.5 ℃, which belongs to the standard of fever, and this time we should find out the cause in time. Most of the causes of fever in children are infectious factors, such as infection with viruses, bacteria or Mycoplasma pneumoniae, which can cause an increase in endogenous pyrogens in the body, which in turn will make the body temperature set point shifted upward, the body temperature set point shifted upward will cause the body to produce more heat than heat dissipation, which will lead to the emergence of the rise in body temperature. Children can be given timely anti-infective treatment, and the fever will subside naturally after the infection is controlled.