Scotland's Andy Murray has overcome scorching heatwave conditions to clear the first hurdle in his quest for a second Wimbledon title.
The world number three beat Mikhail Kukushkin of Kazakhstan in straight sets in his opening game at SW19 in two hours and 13 minutes.
A thermometer inside Centre Court reached a sizzling temperature of 41C (105.8F) on what was the hottest day of the year so far.
Forecasters said that Wimbledon had seen a maximum temperature of 30C (86F), with the mercury expected to reach to 35C (96F) tomorrow.
It would beat the record for the tournament's hottest day ever - 34.6C (94.28) in the summer of 1976.
Officials were forced to limit numbers coming into the All England Club to allow fans to cope with the heat.
A Wimbledon spokesman said that initial capacity had been reduced to 38,000 to allow people "more room in the grounds and therefore more space in the shade and easier access to the free water points".
St John Ambulance said it had been "extremely busy" treating fans.
A spokeswoman said: "I know that it's been absolutely manic for the team at Wimbledon because they have been treating so many people."
One player who was not bothered by the hot weather was seven-time champion Roger Federer, who said it was "totally fine" after winning his first match in three straight sets.
Federer said: "It was perfect conditions, to be honest, it was nice. No clouds whatsoever. So it was straight on, just perfect playing conditions, to be honest."
Asked about a rule that allows women to take a 10-minute break during matches if the "heat stress index" reaches 30.1C (86F), which some have described as "sexist", the Swiss star said he was "happy the way we have it".
The odds of this year's tournament being the hottest ever - beating average temperatures of 25C (77F) in 1976 - were slashed to 2/1 last week.
Fans formed long queues to buy water and looked for the shade to keep cool.
Spectators on Centre Court could be seen putting up parasols and umbrellas during intervals, with many fanning themselves.
In order to reduce capacity officials closed the queue to buy ground passes, which give fans access to courts with unreserved seats, earlier than yesterday.
Among those spotted in the crowd was England football manager Roy Hodgson, who was watching the action from the Royal Box.
A St John Ambulance spokesman said: "As of 6pm we had treated 123 visitors at Wimbledon and transported two to hospital.
"A majority of the people we treated had heat-related conditions but our team have been too busy to extract that information for us."
Asked about the heat, Murray said that it changed the way the game was played.
He told a press conference: "I haven't played loads of matches on that court when it has been as warm as that.
"The day I played Novak in the final, it was extremely hot, but I don't remember playing so many matches at Wimbledon where it was into the 30s.
"The on-court temperature I was told was 41 degrees on court when I was playing."
Murray was also asked about plans to commemorate those who were killed in the Tunisian beach massacre throughout the country on Friday.
He said: "What happened over there was absolutely tragic. It was shocking.
"Because I drive in each day, I've listened to a lot of sort of phone-ins and stuff on the radio, people that have been affected by it. It's absolutely horrific."
On a happier note, Great Britain got four men into the second round at Wimbledon for the first time since 2006 after Aljaz Bedene and James Ward joined Murray and Liam Broady.
Bedene scrapped past veteran Czech battler Radek Stepanek in five sets, while Ward claimed a four-set victory over Italy's Luca Vanni.
British number one Heather Watson also made it into the second round of the women's singles after beating France's Caroline Garcia.
But the 23-year-old was forced to apologise after she was docked a point for using foul language.
Watson had already been in trouble yesterday for "racquet abuse" before her match was postponed due to lack of light.
She told reporters: "I don't even know what I'm doing until after it's done, I don't even realise I'm doing it.
"I say things that I shouldn't say. I apologise to anybody that is offended. I need to control it and I just can't."
Meanwhile, Canadian starlet Eugenie Bouchard avoided punishment after questions were raised over whether her black bra broke the tournament's strict dress code.
The matter was referred by the chair to the Referee's Office but it was decided that no action was required.
Wimbledon's dress code states that players must dress in "almost entirely white" during competitive matches at SW19.
Asked about it afterwards, the Canadian player said: "I was not aware of that at all. And no-one told me anything about my bra."