On Tue, 11 Aug 2020 17:58:41 -0700 (PDT), Nick Cat wrote:

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

totally depends on the house & current temps whether you want it open or
closed at any time.

Well this thread context is summer and it hot outside and requirement
to keep inside cooler. If people are daft enough to not draw curtains
etc thus letting lots of radiant heat in, then opening doors and
windows to "let the heat out", the best they can achieve is making
the house the same temp as outdoors.

Curtains drawn and widows/doors closed up keeps a place cooler.

--
Cheers
Dave.