Altitude - up there

Cusco is at 11,300ft approx. We've been up in the mountains above Cusco today, approxiamately 2.5 miles up in the sky.

The altitude is definitely playing tricks on my breathing. When at rest I'm a slow heart rate, shallow breather. Here I find myself doing the same thing, only every two to three minutes I find chest heaving, my lungs filling to capacity as my body involuntary tries to catch-up with the missing oxygen.

I've been wearing the Garmin today, my resting heart rate this morning was up 12BPM at 60bpm.
From Peru Trip