From the prayer flags, Everest clears Nuptse and catches the last warm light. Reaching this 5,644 m viewpoint demands acclimatisation: keep rest days at Namche and Dingboche, and descend if headache progresses to vomiting, confusion or breathlessness at rest. National park and municipality permits are required; guide and TIMS rules are disputed locally, so confirm before flying. Arrange helicopter-rescue insurance and spare days for cancelled Lukla flights.