The UK has endured the hottest July day on record with temperatures reaching 36.7C.
The Met Office said temperatures hit the record high in Heathrow this afternoon, breaking the previous record of 36.5C set on 19 July 2006 in Surrey.
The high temperatures made the UK hotter than Barcelona, Ibiza and Athens.
Paramedics dealt with a surge in calls amid fears the hot weather could result in deaths.
The London Ambulance Service said it had seen call-outs to people fainting increase by more than a third compared to the same day last week.
Motoring group AA said it had been called out to reports of road surfaces melting in the heat, bringing disruption to drivers.
"The AA are receiving anecdotal reports from patrols that show that in places the road surface is softening, but there are no widespread problems at the moment," a spokesman said.
"There was a man who put the stand down on his motorbike and it sank into the tarmac. The roads are soft in places," he added.
A spokeswoman for Network Rail said metal rail tracks could reach 20C hotter than the air temperature, meaning they could reach 56.7C, prompting fears the steel could expand and buckle.
She said they were monitoring track temperatures and speed restrictions were in place across a number of lines.
Take a look at the record-breaking temperatures across Europe (via @philipbromwell). Also see http://t.co/xbhmCYnvfY) pic.twitter.com/LbOOgmpQpT
— RTÉ News (@rtenews) July 1, 2015
Tennis players and spectators experienced the hottest day in the history of the Wimbledon tournament.
When air temperature, humidity and surface temperature top 30.1C, female players can ask for scheduled breaks between the second and third sets.
While the women's tour rules allow for a ten-minute break, male players are forced to play through the high temperatures.
Currently ranked third in the world, Andy Murray has called on the Association of Tennis Professionals to amend their rules.
"I think the men should adopt it as well, especially because they have to play five sets," said Mr Murray.
Male journalists in the House of Commons were given permission to take off their jackets and ties in the press gallery because of the high temperatures.
Jackets and ties are strictly enforced by Commons doorkeepers, since former speaker Michael Martin tightened standards.
John Bercow, the current speaker, approved a request from journalists as temperatures continued to rise, but held MPs to the normal dress code.
Scottish National Party MP Chris Law was told he must wear a jacket in the chamber.
A v hot day in London & been reminded to put jacket back on in chamber. Real heat will be on PM however #PMQs @NeilGrayMP @AngelaCrawleyMP
— Chris Law MP (SNP) (@ChrisLawSNP) July 1, 2015
