Keep your clothes on, says Tesco as health warning is raised over heatwave

Met Office issues alert amid longest hot spell for seven years

It’s a familiar – if unwelcome – sign that the British summer has truly arrived.

But now some supermarkets are fighting back against the curse of half-naked, sweaty shoppers by demanding that customers cover-up while browsing the aisles.

The fightback has been led by one Tesco store in the seaside town of Newquay in Cornwall, where staff have put up a sign asking patrons to keep their tops and shoes on, so not to put off other shoppers.

“In stores such as this one which are close to the beach, we ask that customers wear a T-shirt and shoes. Whilst we know that many people like to pop in quickly, we ask that people are considerate of others, as we want all of our customers to feel comfortable when shopping,” a Tesco spokesman said.

The “cover-up” sign was put up as temperatures hit a new high for the year, of 31.9C, at Heathrow Airport yesterday, while the mercury is forecast to remain at 31C today.

Today’s high temperature marks the fifth day in a row that the thermometer reading has exceeded 30C, representing the longest heatwave for seven years.

It prompted the Met Office to issue a level-three heatwave alert, warning social and healthcare workers to focus on the very young, the very old and those with chronic diseases.

“Keeping the home as cool as possible during hot weather and remembering the needs of friends, relatives and neighbours who could be at risk is essential,” a Department of Health spokesman said.

“The elderly and those who are ill are particularly vulnerable during hot weather,” he continued.

Police and fire chiefs reiterated their warnings about the dangers of swimming in open water as the hot weather attracted huge numbers of swimmers, and a teenager and a man died at separate lakes at Bawsey Pits in Norfolk. Both were caught in the reeds.

The weather also prompted to police to warn people not to cool down by opening fire hydrants, after a man was arrested for doing this in the Elswick area of Newcastle upon Tyne.

Newcastle West police inspector Mark Farrimond said: “It may all seem like fun and games, but fire hydrants are there for a very good reason – to save lives.”

The heatwave has come about after the jet stream shifted dramatically to the north of the UK at the start of the month, taking it close to Iceland. This colossal river of wind circumnavigates the globe at an altitude of between five and seven miles and speeds of up to 200mph and determines the weather. When it lies to the north of the UK, it drives away unsettled, windy and rainy low-pressure weather systems from the Atlantic, leaving sunnier, drier high-pressure conditions.

A shift to the south of the UK – seen in recent summers – allows colder air to come in from the north that reduces temperatures and increases rainfall.

Yesterday also marked the 15th consecutive day without rain in England, with the last showers occurring on 2 July. This puts England and Wales on course for the driest July since 1825, with just 4mm of rain so far this month. This is just 15 per cent of the average July rainfall, but the Met Office cautioned that it was too early to predict how dry the rest of the month will be.

The heatwave and lack of rainfall continue a highly unusual pattern of weather over the past three years that could have been prompted, in part, by climate change, said Mike Kendon, at the Met Office National Climate Information Centre.

This included a prolonged drought from 2010 to March 2012, which at times was one of the six most significant droughts in the past 100 years. Meanwhile, the four months from April to July last year were the wettest in England and Wales since records began in 1766.