We have quite successfully kept the house a chilly 23 degrees C during this 34 degree outside heat.
We've managed this by buying and fitting blackout blinds and curtains.
Keeping all curtains, blinds and windows shut.
Installing some plastic board covered in tin-foil on a single-pain skylight ( which made the stairs a greenhouse ).
We do currently have a 'portable' aircon but its unlikely that made a difference to anything but the box room its in. Its there to keep the chinchillas cool.
This is after last year, where it got to 36 in our bedroom because of that greenhouse window.
Oh, I've also kept my server turned off in my office.
social.samathy.space is one server in the network