Volkswacht Bodensee - UK hottest June day record broken for third day in a row: Met Office

The 36.9C record temperature was chalked in Wattisham, Suffolk, in southeast England, the meteorologists said, breaking the previous high of 36.7C set on Thursday.

The Met Office has issued its highest level "extreme heat" warning and on Friday extended it yet again for an unprecedented fourth day in a row until 9:00 am (0800GMT) Sunday morning for southwest and southeast England, including London.

The weather agency has warned of "population-wide adverse health effects" as doctors, teachers and climate experts cautioned that the UK was unprepared for increasingly frequent heatwaves due to climate change.

At a market in central London which mainly caters to office workers, street food vendors were struggling to work besides the gas-fired stoves and footfall was down.

"I do just want to stick my face in the ice bucket," said 37-year-old turkey stall owner Will Evans, sporting a green cooling towel he bought online as a bandana.

Working under a black canopy, the chef said it got up to 5C hotter in his workspace, compared to the temperature outside the tent.

According to Evans, public advice to remain at home and limit travel meant fewer officer workers were buying lunch at the market.

At a nearby fried chicken stall, Rainai Almeida said it felt as hot as 43C due to the fryers.

"It's going to be a difficult summer for everyone here in the market, the traders, unfortunately," said the 27-year-old stall worker from Ecuador.

Hospitals and emergency services were stretched thin as well, with London Ambulance Service recording the highest number of "life-threatening" emergency calls in a day on Wednesday, driven by the heat.

"Clinical colleagues who aren't routinely deployed on the front line have been deployed back on the front line," London Ambulance Service chief Jason Killens told BBC Radio 4.

Meanwhile some tourist attractions and museums in London were closed on Friday due to the red heat warning, including the iconic Tower Bridge and the Royal Observatory in Greenwich.

The British Museum said it was closing early and warned it "may also temporarily close some galleries".

Hundreds of schools remained closed or partially closed on Friday, and multiple hospital trusts had raised the alarm after MRI machines and IT systems broke down in the heat.

W.Huber--VB