This document discusses an approach to evaluating a patient presenting with fever and rash. It defines fever and rash and outlines an approach involving assessing severity, confirming fever type and rash characteristics, considering differential diagnoses, and developing an action plan. It then discusses two specific cases: measles in a 9-month old child presenting with maculopapular rash and supportive care is recommended; and rubella with its characteristic rash and Forschheimer spots and no specific treatment required beyond supportive care. Prevention of both involves the MMR vaccine.