This book explores how the lungs function across a spectrum of environments that humans inhabit and/or sometimes find themselves transiently experiencing. The objective of the book is to define the impact of various environments on healthy lungs and how the changes in lung function may have an impact on clinical health. Each chapter is written by an expert author(s) and devoted to the many environmental conditions that humans experience, including high altitude, space, exercise, and underwater. One chapter explores the challenges faced by the respiratory systems of other vertebrate species inhabiting some of these same environments. Two chapters also address extremes in age and how the lungs function under those conditions. This is an ideal guide for practicing physicians in pulmonary and intensive care medicine, trainees, and researchers in the physiology and consequences of breathing in extreme environments.