First flight?

Actually, I doubt it, I suspect the fledgling had returned to the nest.  A few days ago the steady twittering which has come from the box since hatching stopped.  This morning soon after first light I heard them again.   After breakfast, I went out into the garden and there was activity at the nest so I got the camera.  This fledgling's head appeared, moments later half its body was showing, then into this position, a split second later off it flew.

For the record inside temperature varied between 25° and 27 °C the outside temperature reached 35.3°C.

A number of people both on blip and off blip have suggested the house would be cooler with doors and windows open.  I can't get my head round the logic of this.  If you have two buckets one with water at 20°C and one at 25° and take a quarter out of the 20° and replace it with water from the 25° bucket the temperature of the first will rise.  Similarly, if you have a room at 25° and you allow in the air at 35° the temperature of the room will rise.  I can understand that if you happened to get a through draft it would feel cooler (wind chill) but the temperature would be higher.