A temperature greater than 100.4 degrees F is defined as a fever. A healthy child's temperature fluctuates within a normal range. We all tend to have higher temperatures in the later afternoon and into the evening. Fevers are common with many of the routine illnesses like ear infections, throat infections, and even the common cold. High fevers do not cause brain damage. Fever is actually a positive sign that your child's immune system is functioning to fight infection. In fact, some infectious disease specialists even recommend not overmedicating your child with things to bring the fever down. It is also important to realize that it's not necessarily how high the fever is, but how comfortable or uncomfortable your child is with the other symptoms of the illness. As you point out, fever alone may make a child very uncomfortable, and if he is, using one of these medications (e.g., acetaminophen (Tylenol) or ibuprofen (Advil or Motrin) may help.
There are things you can do, other than giving medication, when your child is not feeling well and has a fever. Dress your child in light clothing. Give him a bath with lukewarm water. Encourage him to drink liquids as much as he can and allow him time to rest. If your son is not behaving the way you're used to giving a dose of acetaminophen or ibuprofen may help. If it doesn't, then a phone call to your child's doctor is warranted. How is your child behaving? How comfortable are you with your child's degree of illness? These factors are more important than how high his fever is.