Rob Hall was a very experienced mountain climber. He had scaled Mount Everest five times before the 1996 attempt that ultimately led to his death. In that attempt, or at least toward its end, Hall knew that he wasn't going to survive, and as Wikipedia tells it:
Later in the afternoon, he radioed to Base Camp, asking them to call his wife, Jan Arnold, on the satellite phone. During this last communication, he reassured her that he was reasonably comfortable and told her, "Sleep well my sweetheart. Please don't worry too much."Twenty years ago, being able to hold a telephone conversation from near the peak of Mount Everest to (I think) New Zealand was still a very out of the ordinary event. Today I suppose it hardly raises an eyebrow, though of course the poignancy of that final conversation still makes it special.