You are an airline pilot flying international routes for a major U.S. airline. During an overnight stay in a foreign country, you go out to see the sights and sample the local cuisine. After you return to your room, you experience a crushing chest pain and become violently ill. You go to a local clinic, where the doctor examines you, does a few tests, and tells you that you had a heart attack. By morning, you're feeling fine and believe the doctor was wrong. Is it legal for you to act as a pilot or other required flight crewmember on the return flight to the U.S.? Explain.