Helicopters don't even get close to the altitude. A friend of ours is Britain's top professional mountaineer, Alan Hinkes, the first Briton to climb all of the mountains higher than 8000 metres.
A few years back, during this challenge, he was high on one of the mountains when a sneeze put his back out of joint. Because of the low air pressure at that hight, the disc swelled up and he was unable to move. He could not be rescued because the rescue helicopters can not fly that high.
It was 10 days before he was able to climb down to an altitude where they could pick him up.
Quack!
GtD.