The child’s asymptomatic fever may be caused by acute upper respiratory tract infection, urinary tract infection, acute enteritis and other diseases, which need to be specifically analyzed. 1. Acute upper respiratory tract infection: the child may not be sensitive to the infection, early generally asymptomatic, but due to bacterial toxins and other reasons, it will cause fever, as the course of the disease is prolonged, sneezing and runny nose and other symptoms will occur. 2. Urinary tract infection: when a child develops a urinary tract infection, the pathogen stimulates the urinary tract, making the immune cells more active, and the initial symptoms may only be fever. 3. Acute enteritis: acute enteritis occurs due to gastrointestinal dysfunction caused by improper eating, and may also be due to the presence of pathogens that stimulate the body’s immune system at an early stage, manifesting as fever, followed by abdominal pain, vomiting and other symptoms. When a child develops a fever without other symptoms, it may also be due to causes such as toddler emergency rash, which requires timely examination in the hospital to clarify the cause of the disease and then treat the symptoms.