I am having a war with my children over doors. Usually, parents want them to be shut, but, as London swelters through a heatwave, I am forever opening them. Ideally, the front door to the square and the back door to what we optimistically call the garden would stand permanently open as the garden is, in reality, a yard at the bottom of a canyon of London stock brick into which sunbeams rarely venture, a draft of cooling air would thereby refresh the bottom of the house.

Opening the door to the roof terrace would disperse hot air among the chimneypots, and the members of the Aslet family would sleep as crisp and cool as a £50 note. We have a kind of portcullis across the area door thus, the roof terrace is inaccessible to marauding burglars except by parachute. Yet, whatever I say, I cannot convince the children.

Any external opening is seen as a possible entry point for intruders, viewed not as corporeal beings, but as a miasma, capable of penetrating any crack. No sooner do I open doors than they lock and bolt them, hiding the key.

If global warming continues, however, it will also bring an unwelcome form of cooling to Pimlico, once a marsh. The Thames is almost at the top of the Embankment as it is. We’ll get our feet wet if it rises any higher.