I’ve had windows shut and curtains drawn all day. I have thermal blackout curtains in most rooms, which are also very good at keeping heat out from hot window panes, but the kitchen and dining room windows face south and don’t have them. I have a makeshift solution of some debris netting fixed up over them outside and that really helps.
Now back door and upstairs windows are open to get the air moving through the house. It is 27 degrees C inside now, but got it down to 24 last night. A hot water bottle kept in the fridge all day can assist sleeping if your bedroom is very hot.