On Mon, 10 Aug 2020 08:33:03 -0700 (PDT), wrote:

1. spray the roof with water repeatedly

Well it might make a fraction or two difference to the temperature in
the loft.

2. put a fan in the window during the evening, it blows in outside air
that's cooler

Think I'd go for a fan upstairs in a south facing window blowing out
to extract any warm air along with 5. below. But take note of air
flow caused by the prevailing wind. You want air in from the cool
north.

3. Keep windows/doors (internal and external) closed during the day.

4. Draw curtains and/or close blinds and/or shutters on the hot south
facing sides of the house during the day.

5. Once the external temperature has dropped open windows on the
cooler north side.

6. Have a house with 20 tonnes of thick stone wall running through
the middle of it to absorb any excess heat that gets in.

--
Cheers
Dave.