I'm off work for the next three days, two of which will have no power (as getting earth bonding installed has turned into a much bigger job, including a new consumer unit and lots of other stuff). My mission is to keep things as cool as possible.
It's now 19C outside, 22C downstairs and 23C upstairs - windows have been open for two and a half hours but it's not doing much.
Tonight is meant to be a fair bit cooler than of late (12C, potentially). I will be using the fan on patio trick to try and get some of that lovely colder air indoors early tomorrow - and as tomorrow and Thursday are relatively cool days, it should be very pleasant indoors.