he amber heat extreme heat warning started on Sunday for England and parts of Wales since 41C could scorch the UK start next week.
It has been warned that some people may experience health effects that could lead to potential “life hazard” at the height of the heat wave.
The orange warning also means that substantial changes in working practices and daily routines are likely to be required and there is an increased risk of flood risk incidents and transport delays.
England’s alarm will be red for the first time Monday to Tuesday and the Met Office’s orange warning will extend to the south of Scotland.
A national emergency has been declared.
London commuters have been urged not to travel in the capital and to make only necessary journeys on those days.
The capital’s mayor, Sadiq Khan, held a special crunch meeting on Friday with key senior officials from agencies including the NHS, the Met Police, London Fire Brigade, London Ambulance Service, local councils and Transport for London to review the plan for the level four heat warning to discuss.
Khan has urged Londoners to only undertake essential journeys on Mondays and Tuesdays and to prepare for disruptions as speed limits will apply on train and tube networks.
Temperatures could hit a record high of 41C as the highest temperature ever recorded was 38.7C in Cambridge in 2019.
Additional measures have been taken to tackle the heat wave.
More call handlers, fleet support and extra hours of capacity within ambulances have been set for the hot period.
Steve Barclay told the BBC: “The clear message to the public is to take the sensible steps in terms of water, shade and cover, which many people are aware of. That is the best way to combat the heat.
“We ask people to keep an eye out for their neighbors and those who may be vulnerable.
“We are also deploying additional emergency aid.”