Obviously if your child isn’t breathing, is non-responsive, or has a serious injury like a broken bone, they need to be seen in the ER. A fever in the first two months is abnormal, could be cause for concern and should be treated as an emergency. In older children, fevers cause a lot of worry for parents. But even if your child has a high fever, if they are acting normal they are probably okay. However, a child with any degree of fever accompanied by abnormal behavior such as lethargy or a fever that lasts more than five days needs to be seen by their doctor.