Police officers searching for swimmers who went missing during the UK's heatwave have found two bodies.
A body was recovered on Tuesday evening in the search for a man in his 20s from Wiltshire, who had gone missing in the lake at Cotswold Water Park, Gloucestershire Constabulary said.
On Wednesday morning, Scotland Yard said officers searching for a man last seen swimming in the River Thames at Shadwell Basin on Tuesday had recovered the body of a 23-year-old man.
He had been swimming with friends when he did not resurface, police said.
The death is not being treated as suspicious, with searches continuing to locate two other males also believed to be missing in the Thames.
As temperatures soar across the country, emergency services warned the public to take precautions during the extreme heat and highlighted the risks of cooling off in the sea, lakes and rivers.
The UK is bracing itself for what could be its hottest ever day after overnight lightning storms triggered fires and rail disruption.
According to the Met Office, there is a 60% chance the mercury could rise above the current all-time temperature record of 38.5C on Thursday.
Conditions could reach 39C in southern and eastern England, it tweeted.
With temperatures expected to top 30C in the South East on Wednesday, Network Rail has warned train speed restrictions may be introduced in areas where tracks are at risk of buckling.
Extreme weather action teams (EWATs) have been "activated" to keep passengers safe and trains running, Network Rail said.
The Rail Delivery Group, which represents the industry, advised passengers in London and the South East to consider changing their travel plans on Thursday because of the expected heat.
Director of nations and regions Robert Nisbet said on behalf of train operators and Network Rail: "This week could see record-breaking hot weather for Britain.
"While train operators and Network Rail are working together to minimise disruption, we ask passengers to check before they travel and consider travelling earlier on Thursday if possible.
"We also ask people travelling by train to carry a water bottle and if they feel unwell, get off at the next stop where a member of staff will be happy to help."
Large swathes of the country experienced storms and lightning strikes in the early hours of Wednesday.
Warwickshire Fire and Rescue Service said two engines were sent to a smoke-logged house in Bedworth, near Nuneaton, shortly before 2am after lightning struck an aerial.
Lightning also set a roof annex ablaze and caused a building to be evacuated at around 1.25am in Bowling Bank near Wrexham, North Wales Fire and Rescue Service said.
The Red Cross Crisis Response Centre tweeted that there were three fires caused by lightning during the night.
Lightning damage to a signalling system at Wakefield Westgate station in west Yorkshire led to fewer trains running on Wednesday morning, train operator Northern said.
The storms came after temperatures across England exceeded 30C on Tuesday, with forecasters predicting even hotter temperatures to come.
On Wednesday, the Met Office said temperatures could hit 33C or 34C in the South East and possibly 35C or 36C at isolated points.
Met Office spokeswoman Nicola Maxey predicted it would be a "dry, sunny day, generally very warm, but very hot for parts of the East and South East".
"Generally a good day everywhere once the thunderstorms have pushed out the North East," she added.
The Met Office issued a yellow warning for scattered thunderstorms covering the east of the country from Scotland down to London from 3pm on Thursday and into early Friday morning.
— Met Office (@metoffice) July 24, 2019
It warned that flooding and lightning strikes could affect driving conditions, disrupt train services and lead to power cuts.
Ms Maxey said the highest overnight average temperature (between 9pm and 9am) ever seen in the UK was 23.3C at St James Park in July 1948, and there is a possibility this will be beaten this week.
The average daytime temperature for the UK in July is 19C, which is already being exceeded by evening conditions this month.
On Tuesday night into Wednesday the mercury hit 21C at St James Park.
The hottest ever temperature for July was recorded at 36.7C at Heathrow on July 1 2015.