In reply to planetmarshall:
> ... Parents regularly ask for their children who accompany them on high altitude expeditions such as Everest to be prescribed Diamox or Dexamethasone. Would they feel the same about using THG at a school sports day?
Whereas Diamox, otoh, I have taken prophylactically, which is how it used to be more commonly prescribed, over a decade ago. But that was for a specific and pretty much unavoidable circumstance (flying into LaPaz at 4000m) and for that I think it's OK. But just taken as a precaution, or with views to performance-enhancement, I think it's of negligible overall benefit, from my experience. If you're relying on Diamox to get you up a hill there are other issues you should be looking at - time, schedule, fitness, hydration etc. As a performance enhancer, I think comparing Diamox with bottled O2 is like comparing an espresso with EPO.
As emergency treatment, I've never used it or experienced it, so I really can't say. If the established knowledge says it works then by all means let it be used in emergencies, with descent, Dex and anything else needed to save a life.