In article . com,
"Jay Honeck" wrote:

Nope, but it's a good idea. On this trip, after spending 4 hours at
8500 feet, I felt just fine -- until I tried to compute how far out I
would have to start my descent in order to reach pattern altitude
properly. Suddenly I realized that mild hypoxia had robbed me of my
(already normally challenged) math skills.
It took greater-than-normal concentration to come up with the answer
-- which alerted me to be very careful with my other decisions. (Yet
another advantage of a two-pilot cockpit. I can tell Mary to keep an
eye on what I'm doing, just in case.)

And you were dehydrated because you didn't drink enough water!
Several of us here continue to warn you, and you just won't listen to us.
Buy some piddle packs at the sporting goods store, carry an empty gallon
antifreeze jug, whatever you need, but start drinking water on those
long legs. :-))