The UK’s blistering heatwave “melted roads like chocolate” on Tuesday and warped railway tracks, triggering transport delays across the country.

As temperatures soared to 30C, Public Health England extended its heat-health warning until Friday and urged the public to avoid drinking excessive alcohol in the sweltering conditions.

Meteorologists have warned the mercury could reach 33C over the coming days, overtaking temperatures in popular holiday destinations in Marbella, Mykonos and Tenerife.

Thunderstorms are also set to hit the UK bringing up to 60mm of water in a single hour along with intense lightning and showers of hail, the Met Office has said. 

In Somerset, council workers rushed to repair three main roads which were “melting like chocolate” after the dark asphalt surfacing rose to 50C and congealed in the scorching heat.

Further north in Gloucestershire tonnes of grit were poured over melted tar on sections of the A38 to solidify it and reattach to surfaces.

The heatwave also caused havoc on train services with Network Rail forced to delay four of its services serving Manchester Piccadilly after the hot weather caused a section of a track to bend with cargo trains diverted onto passenger lines.

Railways have buckled in the heat 

Credit: Network Rail 

Chiltern Railway were forced to slow trains down over fears the steel rails could misalign or buckle in the heat, causing delays on services from London to Birmingham and Oxford. 

The delays followed similar measures undertaken by rail operators in Reading and Sheffield. 

Soaring temperatures even prompted South East Water to warn customers that if the hot weather continued they could see their water pressure reduced or even turned off.

Lifeboat and coastguard services have urged families to take care at the coast during the school holidays this summer after a series of drownings over the weekend.

The Royal National Lifeboat Institution (RNLI) and the Maritime and Coastguard Agency issued the plea on Tuesday as new figures reveal a record number of teenagers and children were rescued last summer.

Of the fifty-four children saved last summer, 64 per cent (35) were aged 12 or under, while RNLI lifeguards also came to the aid of another 12,344 under-18s between June and September.

⚠️⚠️ Amber Weather Warning issued ⚠️⚠️

Extreme Heat across parts of South Wales, West Midlands, southern and southwestern England

Valid until 23:59 Thursday

This is the first ever Extreme Heat Warning issued#Heatwave

Latest info 👉
Stay #WeatherAware

— Met Office (@metoffice) July 19, 2021

Meanwhile the Met Office has issued an amber extreme heat warning for parts of Wales, all of south-west England and parts of southern and central England. 

A spokesman for the Met Office said: "The heat is certainly likely to last up to the end of Thursday.

"From Friday onwards there is a strong signal for the heat that remains to be concentrated more towards the north and west whereas parts of England and Wales will start to come back to temperatures near normal."