HAH. I always do my plugs when its cold , wouldn't DARE doing them at any other time. Although I have now twice changed transmission fluid on a hot day 10 minutes after some fast driving Yes. Its hot. Very...very hot. And I always change my oil when I just shut off the car...simply so that all the deposits are mixed up in the oil, not just gonna stay on the bottom of ze pan.

Yet I can relate... I once changed an o2 sensor after 2 hours of driving at 100* temps After one minute, the whole crescent wrench i was holding turned the temp of the manifold perfect eh? forged steel seems to transfer heat quite well.