I have actually never felt hot before during a flight... during delays on the ground and right after take-off it sometimes gets hot but as soon as the air-conditioning has kicked in, the temperature has always become comfortable for me. In fact, I am usually quite cool. Does anybody else feel the same?

But if I had to guess where the coldest part of the aircraft was, I would choose the upper deck, as there are the fewest bodies producing heat, and only a very small hole through which air from the much larger compartments below can circulate through.

Actually, the use of the word "plenty" preceeding an adjective has been common in the USA for quite some time, at least where I have lived, and not an invention of Bush (I believe "grow the economy" was, however). Someone might ask your opinion regarding if some task has been sufficiently completed, to which one can reply "that's plenty good" (translated as "the task has been adequetly completed") and be well understood. May not be Queen's English, but then most of the English spoken in the world is not anyway!