The most common cause of sudden fever in babies is cold, which is often called upper respiratory tract infection, and is the most common clinical cause that can cause fever in babies because their lungs are more delicate and their resistance is poor, so they are more susceptible to wind and viruses, causing fever and symptoms such as cough and runny nose. If your baby has fever symptoms, you should first take your baby’s body temperature, and the principles of handling it at different temperatures are different. The baby’s body temperature is generally 36℃-37℃ in the armpit; 36.5℃-37.5℃ in the anus, and generally more than 37.2℃ is considered to be a low fever. Low fever needs to alert the parents, and the child may have a low fever due to fever from food accumulation, or it may be an initial cold symptom, and the child can be given oral pediatric cold granules to relieve wind and fever. If the child’s body temperature exceeds 38.5℃, you should use antipyretic drugs to reduce fever, such as pediatric ibuprofen suspension, after taking the drug, the child’s body temperature will be reduced, this drug can be repeated every 4 hours. This drug can be repeated every 4 hours. You can reduce the fever of your child and take some antiviral medication at the same time for synergistic treatment.