Why do heatwaves in the UK feel hotter than abroad?

Humidity is the key, Met Office explains

The UK is sweltering in scorching temperatures, with train lines buckling and runway tarmac melting.

A national emergency has been declared for the first time, with the government warning that even fit and healthy people are at risk of illness and death due to the extreme heat.

The Met Office said the “exceptionally hot spell” could have “widespread impacts on people and infrastructure” as it issued its first-ever “red warning” over extreme heat for Monday and Tuesday.

Schools have been shutting or have closed early, trains have been cancelled and people have been urged not to travel unless for essential purposes.

Temperatures hit 38C on Monday, with even hotter weather of 40C or more thought to be possible on Tuesday.

Britons have taken to social media to discuss how the UK’s extreme heat feels hotter than when they have experienced similar temperatures in other countries.

The Met Office has previously explained why heatwaves in the UK may feel warmer than similar temperatures abroad.

“The level of humidity can be higher in the UK than in continental Europe. If humidity is high, it is harder for the human body to keep cool as your sweat doesn’t evaporate as quickly,” a spokesperson told MyLondon last week.

The UK could see records for the hottest temperature ever broken twice in coming days, Met Office says (AFP via Getty Images)

“This is made worse given that we are experiencing more ‘tropical nights’ – nights where the temperature doesn’t go below 20C, meaning we get no respite from the heat and time for our body to recover.”

They added: “Buildings in the UK are also designed to keep heat in, compared to hotter countries. And we are less likely to have air-conditioning.”

Scientists have already warned the UK needs to adapt to better cope with extreme temperatures as our buildings are not built to cope with the worsening climate crisis.

The UK could see temperatures in the 40Cs on Tuesday (Yui Mok/PA)

“We can no longer tolerate poor design of our buildings and our cities, and we urgently need to think about things like reducing overheating, shading, trees, building for cooling, and providing these public cooling spaces.

“We’re not prepared and we’re not built for 40C,” Professor Hannah Cloke, a natural hazards researcher at the University of Reading, said.

Scientists have also suggested other measures homeowners could take to keep their properties cooler in heatwaves, including installing window shutters on the outside of buildings as seen in Europe.

There could also be a psychological factor at play, the Met Office spokesperson suggested, with Britons under-prepared for hotter weather.