Most of the fever in children is caused by viral infections. Fever caused by viral infections has a good mental state and usually lasts for about 3 days, and the whole course of the disease will be completely cured in about 1 week, especially in the first 24 hours of fever, we should pay attention to measure the body temperature, and febrile convulsions occur most often in less than 24 hours. If the mental state is poor with vomiting or if the fever persists, it is necessary to go to the hospital in order to find the cause of the fever and then give appropriate treatment. In the early stage of the disease, it is best to go to the hospital for routine blood tests, according to the results of the tests can be initially determined to be bacterial or viral infection.