The Passenger (1975) on Netflix

David Locke is a television reporter on location in Africa's Sahara Desert. It's hot, humid, and everything seems to be dirty. Returning to his hotel after getting lost and bogged in the desert, he discovers that the man in the room next to his has died. After deciding that his own life wasn't worth living anymore, he switches identities with the dead man, taking the man's passport (with his own photo swapped in), his luggage, and his appointment schedule. Leaving Africa, he heads off to keep the dead man's appointments, hoping that his new life will be more interesting than his old one was.