When a child has a fever, parents should closely observe the changes in his or her condition. Parents should not worry too much because most of the fever is episodic. The child’s temperature is not always proportional to the severity of the illness. Some children may have a high temperature, but their illness may be mild, while some children with a low fever may have a severe illness. If the child is depressed or irritable, coughs frequently, has difficulty breathing or even holds his or her breath, is pale, or has a stiff neck (difficulty lowering the head), vomits violently, or has other serious symptoms, it is advisable to go to the hospital promptly and not to delay the condition. If you have a seizure (even if the seizure has stopped), you should be taken to the hospital. Fever is a frequent symptom of children’s illness. The following are common diseases that cause acute fever in children: 1. Acute upper respiratory tract infection (upper sensation, cold): The incidence of upper sensation accounts for the first place in pediatric diseases. The children have infections of the nose, sinuses, pharynx and throat. In addition to fever, there are symptoms of the corresponding parts of the body, such as nasal congestion and runny nose, sneezing, throat discomfort, sore throat, mild cough, hoarseness, headache and weakness, loss of appetite, vomiting or diarrhea. Some infants and children may have convulsions due to sudden onset of high fever. Most of the upper sensation is due to viral infection, which usually heals itself in about a week. 2, other respiratory infections: such as children with pneumonia, can appear fever, cough, shortness of breath or difficulty, the doctor examination can hear the lungs wet rhodes. The onset is more frequent in winter and spring, often due to viral or bacterial infections, and the condition is highly variable. 3. Gastrointestinal diseases: The most common one is diarrhea. Due to the imperfect gastrointestinal function and low disease resistance of children, fever, diarrhea, vomiting and other symptoms can easily appear if they are not fed properly or after viral or bacterial infections. 4. Acute infectious diseases: common ones are early childhood rash (fever for about 3 days, fever subsides and a small red rash appears all over the body), chicken pox (fever, red rash, blisters and crusted herpes exist on the trunk at the same time), mumps (fever, diffuse swelling and pain on one or both sides of the cheek), scarlet fever (fever, dense small red rash all over the body), measles (fever and cough at first, teary eyes, fever for about 3 days, rash starts to appear), and middle school. The rash starts to appear around 3 days after fever), toxic bacillary dysentery (high fever, convulsions and even coma, with pus and blood in the stool after a few hours or more than 10 hours), etc.