As Nepal’s mountains warm, mosquitoes are spreading dengue, once strictly a lowland disease, to higher-elevation, densely-populated areas.Story by Avery Schuyler Nunn, photos by Yuri SegalerbaThe warming of Nepal’s mountains is dramatically transforming some of the grandest landscapes on Earth, leading melting glaciers to collapse, thawing permafrost that can slide from steep peaks and crumbling ice dams to release vast lakes. But other impacts are barely the length of a fingernail.