A normal healthy 7-year-old walks into the emergency department accompanied by his father, who reports that his son woke up complaining of a stomach ache. "He refused to walk downstairs and is not interested in eating or playing." The child vomits at triage. Vital signs: T 100.4°F, RR 22, HR 88, BP 84/60, SpO₂100%. Pain 6/10. What should be done in this situation?