If a child has a high fever that does not go away, the first thing to do is to clarify what kind of cause it is. A high fever is just a symptom and can occur in many diseases. This includes infectious fever, fever from immune diseases, fever from malignant diseases such as tumors, etc. Infectious fever is common, and the most common infectious fever is caused by viral, bacterial, and mycoplasma infections. At this time, the child’s resistance and immunity are relatively low, and it takes a long time to fight with the germs, so it is easy to have a high fever that does not go away. 1, viral infections cause fever: colds are generally caused by viral infections, the flu epidemic season is caused by the flu virus, when high fever generally about 3-5 days to return to normal. If the baby has a fever, but the spirit is normal, other symptoms are not obvious, you can observe 1-2 days, 6 months to 1.5 years old children should pay attention to the possibility of early childhood emergency. 2, high fever caused by bacterial infection does not go away: more bacteria in the body and keep multiplying in the body, which may cause sepsis, etc. If conditions allow, it is recommended to perform bacterial culture of secretions and drug sensitivity test. Once the diagnosis is confirmed, the physician recommends the use of antibiotics according to the drug sensitivity test, and carefully discusses the indications for use and the time of use. 3. If the pediatrician has a prolonged high fever, attention should also be paid to Kawasaki disease, etc. In conclusion, if a child has a high fever that does not subside, he or she must be seen in the hospital in a timely manner, and attention must also be paid to follow-up. If the effect of taking medication for 2-3 days is not obvious, he or she needs to be seen again in a timely manner to observe the newly emerging symptoms and make a clear diagnosis as early as possible.