Fussy, febrile, and 5 months old: Can you take him at face value?

Q Yesterday, a 5-month-old Latino boy was brought to the emergency department of the general hospital in Denver where you work because his mother was concerned about his three-day history of subjective fever and fussiness, including refusal to sleep. You were out, but today you're handed his chart, and a note catches your eye describing three episodes of nonbloody, nonbilious vomiting and two loose stools the day of presentation.