According to the Met Office, Britain had its hottest day ever on Tuesday with a high of 39.1 degrees Celsius.
According to the U.K.'s weather service, the new record was set on Tuesday morning at 38.6C.
The second day of an extreme heat wave is causing widespread disruption and raising the risk of fires.
The Met Office said temperatures are likely to rise further through today.
A red extreme heat warning has been issued by the Met Office, as temperatures are expected to hit 42C in parts of England. People were urged to stay indoors and drink a lot of water.
According to the European Forest Fire Information System, the southeast of England is at very extreme risk for wildfires.
As many parts of Europe and North Africa are currently experiencing extreme temperatures, there are also fires.
Monday was the hottest night ever recorded in the UK, with temperatures remaining above 25C in many places.
The high in Suffolk in the east of England on Monday was just short of the U.K. record.
The U.K.’s Met Office has said extreme temperatures in the country have been made 10 times more likely by climate change.Several deaths have already been reported as emergency services faced a surge in weather-related incidents.
Many schools didn't open on Monday despite government advice to stay open.
Water companies in the south of England reported an "extraordinary" surge in demand due to the weather, which could result in low pressure or even interruption of supply.
Hundreds of services were stopped as the temperatures soared.
Planes were diverted and flights were canceled because of the heat at the runways at the two airports.
Overhead wire systems failed and rail services were badly impacted. Speed limits of 20 miles per hour were imposed in some areas.
Grant Shapps, Britain's Transport Secretary, said that the country's rail network couldn't handle the extreme heat and that it would take a long time to upgrade it.
Overhead lines that can tolerate higher temperatures are being created. With the best will in the world, this is infrastructure which has taken decades to build, with some of our railways stretching back 200 years, he said.
Due to human-caused climate change, heatwaves are growing more common. Extreme temperatures in the United Kingdom have been made 10 times more likely by climate change according to the Met Office.
Depending on global efforts to cut CO2 emissions, the world's average temperature is expected to rise by up to 4% by the end of the century.
Greg Dewerpe, founder and chief investment officer at A/O PropTech, told CNBC Tuesday as much as $10 trillion per year needs to be invested in buildings and infrastructure to help countries deal with the new climate realities.
He said there is $10 trillion a year that needs to be invested in retrofitting technologies for housing, offices, and all sorts of buildings.
He said that technologies that will enable us to transition in terms of decarbonization and resilience are important.