Children with low-grade fever and headache may be caused by acute upper respiratory tract infections or by central nervous system infections. 1. Acute upper respiratory tract infection: more serious acute upper respiratory tract infection can cause the child to have a low-grade fever and headache, in addition, there can be nasal congestion, runny nose, cough, fatigue and other symptoms. 2. Central nervous system infections: such as meningitis, encephalitis and other central nervous system infections, can also cause children with low-grade fever and headache, but generally more in the early stage of the disease, followed by high fever. Central nervous system infections develop rapidly and can cause abnormal symptoms related to the child’s nervous system in a relatively short period of time, such as vomiting, blurred consciousness, and lethargy. Children with low fever and headache, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.