The hottest day yet of an abnormally sweltering English summer claimed a notable etiquette casualty on Thursday evening, as Marylebone Cricket Club announced a relaxation of its strict dress code for members entering the Pavilion at Lord's.

Spectators attending Middlesex's Vitality Blast match against Hampshire were informed prior to the start of the match, at 6.15pm, that there was no longer a requirement for them to wear jackets in the Long Room, due to the "abnormally warm" weather.

Temperatures in London touched 34C on Thursday afternoon, with the possibility of an even hotter day to come on Friday - potentially threatening the hottest ever recorded in the country, 38.5C in August 2003.

Ordinarily, Lord's dress code for men states: "Gentlemen shall wear lounge suits or tailored jacket and trousers, shirt, tie or cravat and shoes with socks." Women must wear: "dresses; or skirts or trousers (which may be cropped below the knee) or culottes, with blouses or smart tops, and formal shoes, boots or sandals."

However, a tweet from @homeofcricket, the official Lord's Cricket Ground account, ahead of the match read: "Due to the abnormally warm temperatures, MCC has decided to dispense with requirement for gentlemen to wear jackets in the Pavilion and arrive wearing one. This applies to Members of MCC and Middlesex and their guests."

It comes after India's touring team short their ongoing warm-up match against Essex, from four days to three, for what was believed to be concerns about the parched outfield at Chelmsford, and the desire to more closely manage their workloads ahead of next week's first Test at Edgbaston, starting on August 1.

While Lord's has long held a reputation for inflexibility when it comes to dress codes - and other codes, for that matter: it wasn't until 1999 that women were finally admitted to the Long Room - in reality, MCC has relaxed many of its regulations in recent years.

A loosening of the club's famous egg-and-bacon tie - both literally and metaphorically - was first undertaken a decade ago by the club's then-chief executive, the liberally minded Australian Keith Bradshaw, whose efforts to portray the club in a new light also included his championing, on MCC's behalf, of pink-ball floodlit cricket. Further relaxations have been proposed ahead of the launch of the ECB's new city-based competition in 2020, which, with its family-friendly remit, may involve permitting children into the pavilion.

Certainly the club seems slightly less set in its ways than the other two big beasts of the British Social Season - Wimbledon, where in 2015 Lewis Hamilton was ejected from the Royal Box after an "unfortunate misunderstanding" with the dress code, and Royal Ascot, which actually beefed up its dress code this year in a bid to keep a tighter rein on spectator behaviour.

"Additions to the official dress code in 2018 make socks a requirement for gentlemen," according to the Royal Ascot style guide. "Our dress code is traditional, woven into the very fabric of our history."

There wasn't a whole lot of tradition on display at Lord's on Thursday night, where - as Hampshire wilted in the evening heat, losing their last nine wickets for 54 runs in a 22-run defeat - a "kiss-cam" was scouring the stands and zeroing in on amorous couples.

And while they may have been unusually hot under the collar, it is not thought that the cameras lingered too long on the members at this stage of the club's evolution.

Andrew Miller is UK editor of ESPNcricinfo @miller_cricket