Brits have baked in sizzling temperatures with fires breaking out across the country and passengers left to boil on trains.
The country is in the grip of its longest heatwave in four years with temperatures expected to climb further next week.
Brits could scorch in 37C heat come the middle of next week as the Met Office extended its 'amber' extreme heat warning.
The mercury is expected to soar into the mid 30s through the weekend before peaking next Tuesday and climbing to 37C in London, according to the BBC.
The existing record of 38.7C, set in 2019, could be shattered by next week's weather in some parts of the country.
The warm weather has caused chaos up and down the nation, with train firms blasted for "cooking" passengers by leaving the heating on.
Passengers said Southeastern, Chiltern Railways and ScotRail had the heating on, with Twitter user RachNotRakeel writing: “ScotRail is trying to cook us – the train's heating is on, with no windows to open.”
Met Office forecaster Marco Petagna warned: “Even following the extreme heat, it looks often warm in the weeks ahead.”
The boiling weather has seen a number of fires break out across the country, including wildfires on Salisbury plain due to the sweltering heat.
Residents in Chorley, Lancashire, were also warned by firefighters to keep their doors and windows closed as they tackled a huge blaze at a commercial premises in Buckshaw Village.
A number of hospitals have also declared a critical incident due to "prolonged" high temperatures, and beaches have been rammed as the public try to make the most of the warm weather.
In London, Mayor Sadiq Khan has triggered a severe weather emergency response, typically activated when temperatures plummet to freezing in the winter, to support rough sleepers in the capital in the heatwave.
City Hall has written to all London boroughs and rough sleeping services to ask them to conduct welfare checks on vulnerable people and provide sunscreen, water and information about staying cool and safe in the high temperatures.
Mr Khan said: "This ongoing heatwave could be dangerous for anyone, but for people sleeping rough, there are additional risks.
"Across the capital, we are taking action to assist those forced to sleep rough in these extremely high temperatures, by increasing welfare checks, providing plenty of water and sunscreen, and ensuring people sleeping rough know where to access cool spaces and water fountains."
The scorching heatwave, which has already seen temperatures creep over the 30C mark, has even led to some complaints from bin men, with some refusing to collect rubbish and sparking fear that sanitisation services are being put on hold.
South Oxfordshire District Council has informed its residents to leave rubbish out up to two days after their originally scheduled collection if they are not emptied.
South London has also been cited as a place where rubbish collection delays could be seen.
The Daily Star reported that specialist weather teams have been monitoring key hotspots where mercury continues to rise, with drivers urged to keep a bottle of water in their cars.
RAC Breakdown spokesman Rod Dennis has stated that if mercury hits as high as 40C then motorists should "question their decision to drive in the first place".
In Kent, six schools were shut yesterday after a burst water pipe meant they were left without drinking water for more than 24 hours.
They remain shut today, and the council has said four more schools will also close their doors to pupils, due to the extreme heat and lack of water.
Meanwhile, Downing Street refused to rule out a national heatwave emergency today, but said talks are still ongoing.
No10 said there were no plans “at the moment” for nationwide measures, despite a COBRA meeting on Monday to decide whether to declare the first-ever national heatwave emergency.
Boris Johnson ’s official spokesman said: “There will be further coordination meetings throughout the week.
“It’s up to UKHSA [the UK Health Security Agency] and the Met [Office] to decide whether to move further.
“But as it stands there are health alerts for the majority of the country because we expect temperatures to remain high.
"Advice has been issued already both to the general public and to NHS.”
Asked what going further will look like, he replied: “It would depend on the duration and issues like that, in terms of what action the Government or indeed local councils may choose to take.
“At the moment there are no plans to issue national-wide measures but we will wait for further advice from experts like UKHSA and the Met on what the coming days will bring.
“There is already advice for the public which we encourage people to look up.”
The UK Health Security Agency (UKHSA) could declare a “level four emergency” if the heat means that “illness and death may occur among the fit and healthy”.
A UKHSA spokesman told The Telegraph : "There's a possibility of a level four heatwave. If it gets above 40C, then it is likely to be a level four heatwave for the first time."
The Met Office's 'amber' extreme heat warning covers much of England and Wales from Sunday into Tuesday, meaning there could be a danger to life or potential serious illness, with adverse health effects likely across the population, especially among the young and elderly.
