An unlicensed assistive personnel (UAP) reports to the charge nurse that a client who delivered a 7-pound (3,175 gram) infant 12 hours ago is reporting a severe headache. The client's blood pressure is 110/70 mm Hg, respiratory rate is 18 breaths/minute, heart rate is 74 beats/minute, and temperature is 98.6° F (37° C). The client's fundus is firm and one fingerbreadth above the umbilicus. Which action should the charge nurse implement first?