The duration of fever in children with pneumonia varies, depending on the pathogen, and the degree and duration of fever varies, so it is not possible to generalize. In children with pneumonia, the fever is generally exogenous and caused by infection. Children with pneumonia are generally classified as having a low fever of 37.5°C-38°C, a moderate fever of 38.1-39°C, a high fever of 39.1-41°C, and a fever of more than 41°C called hyperthermia, depending on the degree of fever. The duration of fever varies in pediatric pneumonia caused by different pathogens, such as adenovirus infection in pediatric patients, which may present with high fever lasting 2-3 weeks; pneumonia caused by Mycoplasma pneumoniae with fever of 39°C or higher lasting 1-3 weeks, and other pathogens that may present with high fever are Streptococcus pneumoniae, Staphylococcus aureus, and influenza virus. Therefore, when a child presents with poor mental and food intake, it is important to pay attention and immediately consult the pediatric respiratory department to improve the examination and clarify the etiology in order to treat the cause.