When a 3-week-old baby has fever symptoms, it is best to deal with them quickly, otherwise the child will be prone to febrile convulsions and irreversible damage to the child’s brain cells if the child has a high fever, especially if the temperature exceeds 38.5 degrees. Whenever the temperature exceeds 38.5 degrees, the child should be given fever-reducing medication, such as ibuprofen suspension or acetaminophen pellets. If there is a persistent fever or recurrent fever, it is possible to repeat it once after 4-6 hours. It is best to give your child a combination of physical cooling methods, physical cooling can prolong the effect of antipyretic drugs, but also reduce the use of antipyretic drugs, you can use diluted white wine or alcohol, the child’s whole body skin to wipe, the effect is better.