Even against the balmy London nights, I find myself foregoing a cold evening shower for a momentarily comforting warm one. And by warm, I mean hot. A fact I find myself embarrassed to admit until now.

In the mornings, before you jump in the shower, do you brace because you know it’s going to be a chilly dribble? Or do you bound into the bathroom eager to jump into the flow of hot water? If it’s the ...