AUTHOR=West John B. TITLE=Lessons From Extreme Altitudes JOURNAL=Frontiers in Physiology VOLUME=10 YEAR=2019 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2019.00703 DOI=10.3389/fphys.2019.00703 ISSN=1664-042X