Around here its pretty hot in the summer, and general technique is to leave the fuel pumps OFF from engine shutdown until before start to avoid fuel hot warnings before takeoff(especially when tankering fuel into small airports). I cant say for facts if the pumps on actually affects the fuel temperature or not(logic would state so) as I've never paid that much attention to it. All I know is that the one time we did leave them on we had a fuel temp warning on line-up and had to return to ramp to put an extra 200kg colder fuel in to get away
I know slightly OT from the topic, but just wanted to put this out here
-M
Edit: Location is in the mediterranean, not Finland ATM