UBS has just a “few general rules” for its dress policy: “There are no flip-flops, no shorts, and shirts have to have collars. We are not exactly dress-down, but we are more relaxed than many City [of London] institutions. People don’t have to wear suits and have freedom within pretty obvious guidelines. If you are meeting clients, you dress appropriately,” explains a spokesman at the Swiss investment bank.

As the mercury heads north, the thoughts of many in the business community turn to packed, pressure-cooker trains, shirts stuck to backs, constricting ties and just how broadly they can interpret the phrase “smart casual”.