There's no getting around it, we're air breathers. And we like our air with a healthy dose of oxygen. The problem is that some of us air breathers like to go way up in the mountains to hunt or fish or just to wander around. The air is thin up there, and the higher we go, the thinner it gets, leaving our bodies and brains starved for oxygen. If we're not careful, some form of altitude sickness might get us and we might need to be hauled out on a stretcher.