[Engine] Advice on engine noise (fan) after switching off

[lakeside]

I would appreciate any thoughts. I think some cooling activity is normal after switching off but it noticeably going on for a bit longer at the moment. Little driving at the moment my first trip out for a week; only weekly trips to Supermarket since lock down. A noise, I guess a fan, does go off after few minutes. Could it be linked to the air con being switched on which I used today.
I am going on a camping trip tonight, not so far, but don't want to be stranded away from home with a problem.

[brodfather11]

yes it can be linked to the AC cooling down.

[cancunia]

Could also be due to a DPF regen,especially if it's only had short journeys recently.