Normally I'd say leave the AC on. But... the OP lives in United Arab Emirates - so What is a HOT day? 40'C ? 50'C ???
I guess... I'd keep an eye on the oil temps... and IF you see more than 165'C oil temp... maybe turn off the AC.
Btw... during our summer Alpine drive's... I've never had a problem climbing the Alpine passes with the AC on.
Dack
Dack