Do you turn off your air conditioner before bed?

Staying with my grandparents in Croatia, and every night they turn off the AC before they go to bed, and every night around 3 in the morning I wake up, covered in sweat. My dad (who was born in Croatia) does the same thing at home. I'm curious if it's a European, or just a Croatia/Balkan, thing.

Furthermore, if you do, why? Don't you get hot at night?