Britain could bake under record-breaking heat as temperatures could potentially climb to 39C (102.2F) on Thursday.
The scorching conditions may spark thunderstorms which could trigger travel delays, flash flooding, and power cuts.
The dangers of cooling off in lakes, rivers and the sea were highlighted by emergency services after the bodies of three people were pulled from the water on Wednesday after they reportedly got into difficulty swimming.
According to the Met Office, there is a 60% chance the mercury could rise above the current all-time UK temperature record of 38.5C (101.3F) on Thursday.
“It will get into the 30s across the country and reach the mid-30s in the South Eeast,” Met Office meteorologist Greg Dewhurst said.
“If it is to get to 39C, it will happen somewhere between London and Cambridge.
“Temperatures locally could also break July or all-time records.”
Network Rail warned speed restrictions may be introduced in areas where tracks are at risk of buckling.
Extreme weather action teams (EWATs) have been “activated” to keep passengers safe and trains running, it said.
London North Eastern Railway (LNER), which runs inter-city services on the East Coast Main Line, is advising customers against travelling on Thursday.
It said some services were likely to be cancelled or delayed as speed restrictions will be imposed between Peterborough and London King’s Cross.
Those making long car journeys cannot rely on the radio for company – FM and AM radio signals can be disrupted in hot weather because signals from local stations can travel further and cause interference outside their usual range.
Keep an eye on our social media channels today as we’ll be updating you with the latest on the temperatures. On that note, we are already at 25 °C at Kenley Airfield ?️ #heatwave #HeatwaveUK pic.twitter.com/DGPSKDmWFz
— Met Office (@metoffice) July 25, 2019
The Met Office has warned heatwaves are on the increase as a result of climate change.
It is even possible the mercury could climb to 40C (104F), which would be “unprecedented” for the UK climate, weather forecasters said.
The scorching temperatures gripping the UK and much of Europe come against a backdrop of global warming of 1C since the Industrial Revolution driven by greenhouse gas emissions.
Both Belgium and the Netherlands broke their all-time maximum temperature records on Wednesday, reaching 39.9C (103.8F) and 39.1C (102.4F) respectively, the Met Office said.
Higher temperatures are making extreme hot spells more likely and more intense, experts warn.
