Chapter Five: Snowdon versus the Sherpa:

http://etd.lsu.edu/docs/available/etd-0328102-102651/unrestricted/5.Chapter(Haltrin).pdf

You know, why bother? Either you are on the trek or you aren't. For those who are actually on the trek, here is some advice:

Watch out at about 5.000 ft. Snows deep and huge crevasses open up to expose the story of historical ressurrections. For the ascender, this can be quite disturbing until he/she realizes it wasn't snow at all under the feet but instead, frozen and paradoxical.