Over 60 degrees C, in Kuwait, but that was in the sunlight (not how temp records are measured, and different to shade temps). I actually think it was hotter but the thermometer couldn't hack it, it was about 50 in the shade recorded at the weather station
It was exceptionally dry and I was acclimatised, so whilst like an oven it wasn't the hottest or most uncomfortable I've felt, that award goes to Qatar and it was about 43 I think, but with much higher humidity, now that was awful, and a lot more sandstorms too.
The 60 degrees still isn't the hottest I've been mind, short term, being in an aircraft cockpit, with an almost closed canopy, on a tow, without the ECS/ Air Con on was something else, it must have been 80 degrees C. I know most won't believe that, especially those that haven't been in the forces or to the gulf, but if you've not been in the situation, you wouldn't think it was possible. I was cuddling multiple frozen 2ltr bottles of water to keep me cool
Most of the lineys (aircraft mechs) did it at some point, but we tried to avoid doing it during the day. When the canopy opens again, you feel really cold, but it's over 45 degrees C, it's strange.
As for cold, I'm sure it got down to about -10 to -14 here in the 80's/90's? I've been about -20 in Canada, and maybe even -25 when skiing up the top of Tignes, but with wind chill it was bloody cold on the face when you weren't moving and you're not there, that high/ cold for that long.