The causes of fever in newborns under 1 month of age are: overdressed, dehydration, cerebral hemorrhage, various infectious diseases such as meningitis, pneumonia, septicemia, umbilical cord infection, etc. The main causes of fever in children over 1 to 2 years of age are: colds, pneumonia, enteritis, meningitis, vaccination side effects, medication side effects, etc. The main causes of fever in children from 2 to 5 years old are: various respiratory infections, urethritis, meningitis, enteritis, arthritis, otitis media, tonsillitis, cancer, etc. The main causes of fever in elementary and junior high school students are: colds, osteomyelitis, pneumonia, tuberculosis infection, tonsillitis, hepatitis, myocarditis, hyperthyroidism, arthritis, etc. Among them, colds are the main culprit of fever in children, and more than 90% of fevers are caused by colds. How can I tell whether to take my child to the hospital immediately? When a child has fever, in addition to taking the child’s temperature, you should also observe the child’s performance and mental condition. If the child is still able to eat and play as usual, parents can always breathe a sigh of relief, because most of the children do not have a big problem. However, if the child has the following conditions, we should rush to the hospital: fever with vomiting; fever has gone down, but the child is still in poor spirits, poor spirits; fever with dehydration, no urine for more than 6 hours. In addition, infants and children under 5 years old are prone to induce convulsions when they have a high fever, so it is important to reduce the fever. You can undress the affected child and scrub the body with warm water. If this doesn’t work, give the child an antipyretic if the temperature is over 38.5. Choose your child’s antipyretic carefully. There are 3 common antipyretics, paracetamol, ibuprofen and aspirin. Among them, paracetamol has minimal side effects on children. It is best to use it under the guidance of a pediatrician. The amount should not be too much at a time, follow the instructions and calculate the amount needed for each time according to the weight. In general, do not take more than 4 times a day. Note that children with chicken pox, viral colds, don’t choose aspirin, because children with viral colds can cause Reye’s syndrome if they take aspirin. Viral colds, asthma, children with bleeding tendencies, premature babies, and newborns should not take aspirin.