Jack Kerouac (#2). Photo: Devin Smith

N ot long ago, I tried to have a suit made of gray flannel, but was told that, being a thick and heavy cloth, flannel was no longer in demand. Buildings are so well-heated these days, said the tailor, that flannel is uncomfortable to wear in them. Here was an indisputable consequence of global warming.

My attitude to gray flannel has changed over the years. Since my first school uniform was of that material, I associated it for a long time with immaturity and a position of subordination to others. Then, as a young doctor, I came under the spell of a most distinguished man, one of the Queen’s physicians, who was learned,...