The French, Italian, and Spanish governments have issued red heat alerts. Temperatures are set to hit 40C. The NHS has followed up with a travel warning for Britons heading to the continent.
This is not a drill. This is a public health emergency. The Met Office has already flagged the risk of heat exhaustion and dehydration for vulnerable groups. The Foreign Office is coordinating with airlines and tour operators.
Sources inside the Department of Health tell me they are preparing for a surge in calls to NHS 111 from panicked travellers. There is talk of a dedicated helpline being set up.
But the real story is the politics of heat. Whitehall insiders are privately warning that this could be a dress rehearsal for a larger crisis. A senior civil servant said: "We are not ready for 40C summers in the UK. The infrastructure is not there."
Backbenchers are already sharpening their knives. Expect questions in the Commons tomorrow. The opposition will demand to know what the government is doing to protect British citizens abroad.
One Labour MP told me: "The Tories have cut funding for the Foreign Office again. Now we see the consequences."
The timing is brutal for Downing Street. The PM is already on the back foot over the economy. A heatwave that kills British tourists is the last thing they need.
The NHS travel warning is unprecedented for a heat event in Europe. It was issued after a meeting of COBR this morning. The decision was taken by the Chief Medical Officer directly.
Inside sources say the CMO was concerned about the number of elderly Britons who travel to southern Europe in July. Many have pre-existing conditions. The combination of heat and lack of air conditioning is a deadly mix.
Tour operators are now facing a PR nightmare. Jet2 and Ryanair have been contacted for comment. A Ryanair spokesperson said: "We are monitoring the situation closely. Passengers should check the FCO website for updates."
The real test will come if temperatures exceed 42C. That is the threshold at which flights can be grounded. Whitehall planners are already modelling that scenario.
For now, the message is simple: check on elderly neighbours. Avoid the midday sun. And if you must travel, carry water and a phone charger.
This story is developing. I have a source in the French health ministry who says red alerts could be extended to Germany by Friday. The heatwave is not moving north.
The British public should brace for a summer of extreme weather. The government is not ready. And the opposition knows it.
