In the Sonoran Desert, between Arizona and California, hundreds of migrants crossing from Mexico into the United States lose their way and die, mostly from dehydration, under the 50 degree temperatures of the hottest desert in North America. This border region is the most dangerous land-crossing in the world, according to the International Organisation for Migration (IOM). BBC Mundo followed a group of volunteers, the 'Aguilas del Desierto,' on one... see more