Heather Hansman loves skiing. In her 20s, her life revolved around the sport. Later, she covered it as a journalist. Now, she’s written a book about skiing and the people who love it, as well as the uncertain future of a sport that depends on certain weather conditions. She examines the race, class and gender inequities in the world of skiing, as well as the mental health struggles some devoted skiers face. We talk with Hansman about “Powder Days: Ski Bums, Ski Towns and the Future of Chasing Snow.”