A fever can be caused by a number of things, but in a child it is usually a sign that the body is fighting an infection, creating an environment that is inhospitable to the infectious agent. And for this reason, the fever is actually a good thing. Although high fevers should be treated, often you can let your child's appearance guide you. If the child appears otherwise comfortable and behaving normally, a lower grade fever (100-101°F) can be watched as it is doing its job to rid your child of the infection. Some important numbers to keep in mind though: any temperature higher than 100.4°F in a child less than 3 months needs to be brought to the attention of your doctor imnmediately. I also advise parents to call me if their child has a fever that is not responding to medication, or has persisted intermittently for more than 24hrs. If in doubt, always call your doctor.