At the top
I made a small hike while at Glacier National Park, which was a fairly steep grade in melting snow.
While the elevation was somewhere near what I was used to when living in Salt Lake City, it still kicked my ass. Those at sea level don't realize such simple hikes at a moderate elevation can simply kill your lungs. Not literally of course.
I still remember mountain biking and feeling as if my brain was going to squirt from my ears from the height when in the mountains.
As for these two, they were gasping for some air. Not sure where they were from, but obviously they needed some oxygen and weren't finding much.