Record temperatures have caused chaos in the London Marathon, with runners struggling in the 23C heat.
More than 40,000 runners took part at St James's Park on Sunday, with the peak temperature of 23.2C setting a new London Marathon record.
The previous high of 22.7C was recorded in 1996, while it hit 22.6C in 2007 - when one runner died and 73 were hospitalised.
Organisers said temperatures were much higher on the course due to the heat from the road and other runners.
“A big caveat here is obviously a weather station temperature record will feel a bit different to what it might feel like trackside where you have the warmth coming up from the tarmac and other people,” Met Office spokesman Grahame Madge said.
Event director Hugh Brasher said four-and-a-half litres of water per person was distributed - more than any other mass participation event in the world - but it did run out at some points.
The high temperatures would have been especially difficult for runners in fancy dress.
“We reminded them they should adjust their goal for Sunday and plan to run at a slower pace and, if they were planning to run in fancy dress, they should think carefully if that is appropriate in these conditions,” Brasher said.
Eliud Kipchoge won the event for the third time, with Mo Farah breaking the British record as he finished third, while there was a surprise victory for Vivian Cheruiyot in the women’s race.
Kipchoge, who skipped last year’s race to attempt a sub-two-hour marathon in Italy, could not break Dennis Kimmetto’s world record as high temperatures made running conditions difficult in the English capital.
Women's favorite Mary Keitany attempted to break Paula Radcliffe’s “mixed race” record -- assisted by male pacemakers -- but the Kenyan struggled late on in the race, eventually finishing fifth and unable to add to her three London titles.
That allowed Cheruiyot in to take her first London crown, having won her first career marathon in Frankfurt only in October.
Radcliffe’s record, set in 2003, did seem under threat at first as Keitany comfortably led for the majority of the race but the conditions got the better of her in the end.
The men’s race went out at a blistering pace, with early leader Guye Adola clocking four minutes 22 seconds in the first mile, and Farah stayed with the group until a bizarre incident when he missed his drinks bottle around the 10-mile mark, which delayed him after a heated exchange with a steward.
"The drink station was confusing, I was table four, I went to pick it up," Farah told the BBC. "The staff were helpful at the end but at the beginning they were trying to take a picture rather than giving me the drink.”
Kipchoge overtook Adola early on and led from the front, with the pace remaining on course for a world-record time until the second half of the race, when the heat intensified.
Tola Shura Kitata of Ethiopia stayed with Kipchoge until close to the end but the 2015 and 2016 champion strode clear to win with a time of 2:04:17 -– two minutes 20 seconds off the world record.
Officials initially gave Kipchoge's time as 2:04.27 but revised the times after discovering a computer error.
Farah came home in third, finishing with 2:06:21 and breaking Steve Jones's British Marathon record which has stood since 1985.