[Answer]
When I am asked how illness is different for adults and children, I usually reply that compared with adults, children often have fevers and they are not able to relate their own symptoms very well.

It proves true in the case of infants with a fever at night who can't describe their symptoms (where it hurts or what is painful).

When an older child or adult suddenly has a fever at night, he or she can relate any accompanying symptoms, such as a sore throat or splitting headache. In the case of a sore throat, it is possible to wait until the next morning, but in the case of a splitting headache, even someone who is not a professional in the medical field knows that you need to go to the nighttime emergency center.

Only knowing that the child has a fever and without information about other symptoms, parents assume the worst-case scenario and want to immediately go to the nighttime emergency ward.

In fact, a high percentage of emergency ward patients at regular hospitals are children, and the most common reason for seeking medical care is fever. And as it turns out, only a few of these children need to be hospitalized immediately for treatment.

When I was a doctor on duty in the pediatric ward, I talked on the phone with parents who sought a diagnosis for their child's sudden fever at night and gave them advice on whether emergency medical care was necessary or not.

Let me explain the criteria that I use to determine whether a child running a fever should be brought to the hospital immediately or whether it is possible to wait and see.

First, let me make clear that the degree of the fever (body temperature) is not a very good basis for making this decision. This judgment should be made based on, first, symptoms other than the fever and second, the child's overall physical condition.

Other than fever, other significant symptoms include (1) coughing (2) diarrhea (3) rash (4) vomiting (5) respiratory condition (6) abdominal pain (7) convulsions and (8) impaired consciousness. By looking at symptoms other than fever, it is possible to know the cause of the fever and the locus (location of the illness).

The decision to take a child with fever and a cough to the emergency ward or not depends whether on the fever is due to a cold or pneumonia. In the case of a cold, seeking urgent medical advice is not necessary. Determining whether the condition is pneumonia or not depends on how strong the cough is, whether it is a wet cough that brings up phlegm, and the child's general physical condition. If the child cannot sleep, lie down, and eat at all due to coughing, seeing a doctor is advised because it could be pneumonia.

If the child has a fever and diarrhea, and is unable to eat due to vomiting and nausea accompanied by severe abdominal pain, urgent medical examination is advised. If the child is able to eat and drink and has no abdominal pain, I would recommend watchful waiting at home.

In most cases, when the child has a fever and rash, this indicates viral infection. Urgent medical examination is advised only in cases when the child displays general symptoms such as drowsiness, being unable to eat or sleep. This applies to illnesses such as Kawasaki disease. In other cases, it is all right to take the child to the hospital for a medical examination the following day.

In the case of fever and vomiting, I recommend seeking medical advice immediately in all cases. This is because meningitis and encephalitis are also serious diseases that are characterized by such symptoms as fever and vomiting.

In the majority of cases, the main cause of breathing difficulty is asthma, not fever. In the case of a fever and breathing difficulty, pneumonia is a possibility, and urgent medical examination is advised.

If the child has both a fever and convulsions, or shows impaired consciousness, seek emergency treatment immediately. In all cases except one, these are symptoms of a serious illness such as encephalitis, meningitis, and acute encephalopathy. The only exception is when the child has had febrile convulsions in the past. If the convulsions subside, it is not necessary to seek medical advice.

I hope this information has been helpful. Of course, these diagnostic criteria will not be applicable in all cases, therefore I suggest the ultimate decision be made by the parents.