Everest is on the left side in the back. About 12 years ago I was on a climbing trip to attempt Cho Oyu which is the 6th highest peak and about 20 miles west of Everest. Mant of our climbers got a cold before base camp and I caught it right before moving from base camp at around 16,000 ft to high camp at around 18,500 ft. It turned into pneumonia and I had to go down.
The highest peak I have summited is Cerro Aconcagua in the Argentina Andes by the Polish Glacier route which is probably the second hardest route after the south face route. Aconcagua is just under 23,000 ft and the difficulty near the top was about 4 breaths for every step (no oxygen) and around minus 15F at the warmest time of the day. The climb took 21 days total in and out and the summit day started at 3 a.m. from high camp at 19,500 ft and we summited at 4:00 p.m. and back down to high camp at around 11:00 p.m. I lost 25 pounds, 175 to 150 in three weeks. During the short climbing window (maybe 8 weeks) in the south american summer there were around 7 fatalities on Aconcagua that year. Many were for inproper altitude acclimation. We hauled gear into base camp at 14,000 ft using hired mules, but then did two load carries (about 75 lbs each) to 16, 500 ft and then 19,500 ft camps with a rest day between each carry day. Got pinned in tents by high (over 80mph wind and minus 25F weather.
After Cho Oyu I wouls never try Everest. Two Sherpas on a S. Korean expedition were ahead of us on Cho Oyu and were fixing ropes when they were blown off the mountain when a storm came up with estimated 150mph wind. They were never found.
Any experience with the Puna? The friend that I wrote about in post #13 decided to summit Cerro Aconcagua a couple of years after the events I described. He fell prey to the Puna, wandered around for several days (it's been a long time, I don't remember) and was finally found by some locals. He had suffered frostbite to the tip of his nose, when I met him in Madrid several months later it was black, and it eventually had to be removed.