Children with fever without cold symptoms may have infectious diseases such as acute gastroenteritis, meningitis, or non-infectious diseases such as malignant tumors and allergies. 1. Infectious diseases: such as bacteria or viruses and other pathogens infect human tissues or organs, can cause the body to undergo an inflammatory response, under the action of inflammatory factors, fever symptoms can occur. 2. Non-infectious diseases: such as leukemia, leukemia cells can be used as a pyrogen, leading to the phenomenon of fever in children; such as drug allergies, after taking drugs such as clindamycin, may cause fever and other adverse reactions. When a child has an unexplained fever, it is recommended that parents take their children to the hospital in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor to avoid delaying the condition.