540
Someone put up a tent on their balcony to escape their heat-trapping apartment during the night.
(discuss.tchncs.de)
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.
.
Not that I didn't try the fan solution. Done properly, I managed to reduce the air temperature by about 1°C by early morning compared to the evening.