Constant comfort

sir – In the Fifties, I was pleased to have the comfort of my red hot water bottle (with a knitted cover, made by my mother, with a capital K on it). Now 71, I still have a hot water bottle of exactly the same design and efficiency, including the winged stopper.

With so many products being frequently updated, is this the perfect design, and, if not, what improvements are possible?

Kevin Pearson

Newbury, Berkshire