You receive a call at the pediatrician's office from a woman with a 6-month-old daughter who has been experiencing vomiting and diarrhea for the past 24 hours. Her daughter has an axillary temperature of 99.2º F. The mother says that her child has been irritable and can't keep anything down. She asks if she should bring her baby in for a visit or wait and see if the vomiting subsides. How should the nurse respond?