Roads have been melting in parts of England as the heatwave across most of the country continues.
Gritters spread sand onto heat-damaged roads in Cumbria
Gritting lorries have been sent out to spread crushed rock dust on melting tar to create non-stick road surfaces.
Monday was the year's hottest day so far with a reading of 32.7C (90.9F) at Heathrow. Forecasters say temperatures could be 37C (99F) later in the week.
The average maximum temperature in England for this week in July is only 21-23C (70-73F).
Forecasters expect the South East to experience the highest temperatures again on Tuesday but there has been record-breaking heat elsewhere in the country.
HOTTER THAN NORMAL
Predicted highest temperature and average for this week
South East 37C - 23C
East Anglia 37C - 22C
Midlands 36C - 22C
South West 36C - 21C
North West 35C - 20C
North East 33C - 21C
Source: Met Office
BBC forecasters in Yorkshire said the county reached its highest July temperature ever with 32C (90F) at Linton-on-Ouse, while forecasters in the West of England said the region could have its hottest July day for more than 100 years on Wednesday.
Much of England has reached official heatwave conditions, according to the Met Office, with London, the South East, the South West, the East Midlands and the West Midlands all experiencing a heatwave.
Even the region least affected by hot temperatures so far - the North East - has an 80% chance of reaching heatwave conditions by Friday.
The Met Office recommended people stay hydrated in the heatwave conditions and Transport for London repeated its advice to passengers to carry water with them on the Underground.
Crowds flocked to beaches in seaside resorts such as Brighton
Precautionary speed restrictions were in place on outdoor stretches of track on the District, Piccadilly, Metropolitan, Jubilee and Northern lines.
A trial at Preston Crown Court was halted for the day on Tuesday when jurors said it was too hot to concentrate - the judge had already allowed barristers to remove their wigs.
Council gritters - usually associated with treating icy roads in winter - have been sent out or put on standby in Durham, Staffordshire, Lincolnshire, Cornwall and Cumbria.
Children at a junior school in York are to be sent home early because of the hot weather.
'Wilting at desks'
The head teacher at Scarcroft School - where temperatures have reached 32C (90F) in some classrooms - has told parents it will close at lunchtime on Wednesday, Thursday and Friday.
Heat caused railway lines to buckle in the Midlands, while glass panels fell at a Newcastle bus station.
The TUC has called for workers to be allowed to dress more casually as a way of avoiding "staff wilting at their desks".
Fans at the Open golf practice days have had heat to contend with
Organisers of the Open golf tournament, which starts at the Royal Liverpool course in Hoylake on Thursday, fear the weather could affect playing conditions, with greens needing to be watered if they get too dry.
On Monday temperatures in the South of England topped those in Spanish resorts, higher than in Ibiza, where it was 31C (88F) and the Canary Islands - 27C (81F).
The BBC Weather Centre said it expected London temperatures to reach 37C (99F) on Wednesday, breaking the July record of 36C (97F), seen in Epsom, Surrey, in 1911.
BBC weather forecaster, Tomasz Schafernaker, added there was a "10% chance" the UK's all-time record of 38.5C (101F), recorded in Kent in August 2003, could even be beaten.
"On Tuesday and Wednesday, temperatures in the Midlands will rise to around 34C and 35C so already there will be some local records broken for July," he said.
He said temperatures would ease off to around 30C in the Midlands and South East on Thursday and Friday.