Hufty,
You're right, that does sound strage. Surely you could ask an instructor to check you out, even if they don't actually require the check-out?
Anyway, I did this checkout myself about 18 months ago, in Arizona. Wasn't all that hot, since it was winter, but definitely high. The most important thing is to check the performance figures in the POH. There's really no secret to it - if the manual says you can make it in with a safety margin then go, if not then don't go.
As long as you've checked the graphs properly, there isn't very much more to say about the actual take-off and landing. The groundspeed will be faster, but you should be used to varying groundspeeds anyway because the groundspeed depends on the windspeed even at sea-level - so it may feel like you have a small tail-wind in terms of your higher groundspeed. Personally, I didn't really notice this. Climb performance is only really an issue if you're taking off directly towards a cliff face - it wasn't something I worried about at all while I was over there, other than to accept that it takes a while to get to 10,000'.
The other thing you need to understand is mountain weather. Never fly towards a mountain unless you have a get-out plan in case of a strong vertical wind. Try to stay a few miles away from mountains, especially if downwind of them. As long as you stick to those two rules you should be safe.
Talk to local pilots as well as instructors. But the main thing is to stay safe, be cautious - and enjoy it!!!
FFF
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