London | People in large parts of the UK are being warned that high temperatures will present a risk to life on Wednesday as a "heat-dome" over Western Europe brings extreme conditions to the continent.
The "red heat health" alert for much of central and southern England, as well as Wales, is only the second such warning ever issued by UK authorities. The first was in July 2022, when temperatures exceeded 40 degrees C (104 F).
Authorities in France, Italy and Spain have also issued warnings about the risks of extreme heat for tens of millions of people.
The UK is braced for the highest ever June temperatures, with the Met Office forecasting a high of 38 degrees in southern England. Temperatures reached 34.6 degrees C on Tuesday in Wisely, southwest of London.
"Red warnings are reserved for the most severe events and we're expecting severe and significant impacts from this heat wave, with health impacts likely for many, even beyond those who are normally more vulnerable to the heat," said Mark Sidaway, deputy chief forecaster for the UK Met Office.
Some schools in England are closed due to the heat and many train services have been cancelled with passengers urged to avoid non-essential travel in areas covered by the red warning.
Network Rail, which operates Britain's railroad network, warned of "significant disruption" across England and Wales as it imposes speed restrictions to minimise the risk from heat-related issues such as buckled tracks and sagging overhead electric wires.
Eurostar said it cancelled four trains planned between London and Paris on Wednesday and Thursday "due to expected adverse weather".
France recorded its hottest day ever on Tuesday, prompting the Eiffel Tower and the Louvre museum to restrict visiting hours while schools and transportation schedules were upended.
The record of 29.8 C (85.6 F) for France's national thermal indicator - an average of temperatures measured at 30 weather stations - was only the latest in a series of never-before-registered highs heaped on Europe's largest country.
Italy's Health Ministry issued "red alerts" for 16 cities on Wednesday with major cities such as Rome, Milan, Florence and Turin affected. The "bollino rosso" red alert signals emergency conditions that can affect not only vulnerable people but also healthy adults.
Temperatures could reach highs of 41 C (105 F) in Florence and 38 C (104 F) in Milan, while Rome and Naples are forecast to remain below 36 C (96.8 F).
Britain's heat advisory remains in effect through Thursday, with overnight temperatures remaining well above average.
It's so hot in the tradition-bound seat of British democracy that male journalists covering Parliament are being allowed to remove their jackets in the press gallery of the House of Commons on Wednesday.
"If you think it's hot already, well, we ain't seen nothing yet," Met Office meteorologist Alex Burkill said on Wednesday morning.
