Klaas Willems on El Capitan, 700 meters above the valley floor in Yosemite, doing aerosol therapy for his Cystic Fibrosis during a 6 day ascent of the Pre-muir Wall with fellow Belgians Nicolas Favresse and Sean Villanueva O'Driscoll. 'I prefer doing my therapy outdoors than in hospital. Good memories from 2017'

© Sean Villanueva O'Driscoll