Our family of 4 stayed at Nadine's place during the intense heat wave where Heathrow reported its highest temperature ever. The a/c was much appreciated, and the location of the flat is well situated. Nadine allowed us to check in a bit early, and met us upon arrival to show us how things worked - this was very much appreciated. But as other reviewers have mentioned, the bedrooms allow a lot of light as they face due east. As most guests are enjoying London all day and perhaps like us, enjoying multiple shows late into the evening, room darkening shades would be much appreciated to allow us to sleep in comfortably longer.
We also had a major issue with the water temperature in the bathrooms - Nadine claimed that because of the high temps, that the plumbing could not provide cold water - so even with the water at the coldest setting, all our showers were hot, hand washing was only with hot water and even the toilet water was hot. There is also a towel drying rack in the main bathroom that is constantly on and radiating heat - so even with a/c, the flat is fighting with itself to maintain a comfortable temperature in the warmer months. Note that even when temperatures dropped, the water was always quite warm and as other reviewers have indicated, the temperature when showering was not consistent. I believe that cold water is a basic expectation when booking a place, so although we enjoyed our trip to London, I have to leave an ok rating for this flat. To be clear, we had traveled for four weeks before arriving in London, staying at multiple AirBnB's during heatwaves throughout Greece, Italy, Germany and France - this was the only flat we had an issue with water temperature, and in this case, it was extreme.