Third extended heat wave within 6 weeks.
The previous one exceeded 40°C, and the buildings not yet had time to completely cool down from that one before the third wave hit.
I was considering putting up a tent in my garden myself, but as I own a ground floor flat, the indoor temperatures did, with the help of some additional cooling measures, thankfully not exceeded 27°C.
Open windows make it so much worse if the air is very hot and/or there is no wind - which is often the case in many places
Said that, i syill keep them open because i got one of those fans that cool air using water which makes a lot of humidity that somehow i need to remove