I recall the day in June, 1990 when my wife and I were moving from LA (Fullerton, actually) back home to Dallas, driving two cars; it was 122 or 123 in PHX as we drove through, and for a time, many flights were ancelled or delayed; at the time, my understanding was that the big problem was not that the aircraft were unable to fly and fly safely, but rather, that the POH (Pillot's Operating Handbook) for the various aircraft did not contain data for the higher temps and, therefore, the flights could not be operated within compliance with the book. It was also reported that Boeing, McD and others were faxing amendments to the POH's to the various airlines so the books could be officially updated, and the flights could legally operate.
It was HOT!
But my 1976 ElDorado, with a radiator as big as a bed, ran just fine, and the AC kept me quite comfy.
...three miles from BRONS, clear for the ILS one five approach...