Reinforce floor slab insulation, reduce heat entry into the upper floor

....we may soon be facing a similar question as well. We still hope that it can be done without climate......we'll see.

No matter which U-values you add or weigh against each other,
outside it is hot, 35 degrees during the day and hardly cooler at night,
the house heats up and doesn’t lose the heat anymore, only if you bring in cooling power, with air conditioning, will it get cooler.
The Mediterranean construction method is out of the question regarding window areas,
so California construction method, lots of glass and air conditioning.
Often it is enough to run with low power to make it comfortable.
And as you say, heat rises upwards, one air conditioner in the bedroom and one in the living area, minimum.