Rafael Nadal claimed it was "dangerous" to finish his French Open quarter-final at 1.30am following victory over Jannik Sinner in the tournament's latest ever finish.
Nadal, the 12-time champion, defeated 19-year-old Sinner 7-6 (7/4), 6-4, 6-1 to clinch a 98th victory in his 100th match at the tournament and stay on course to equal Roger Federer's all-time record of 20 grand slams.
However, Nadal, more accustomed to the bright sunshine of Mallorca than the autumn chill in Paris as temperatures plummeted 12 degrees, was unhappy with organisers who scheduled five matches on the main Court Philippe Chatrier.
"I know footballers play under these conditions, but they are all the time moving," said Nadal.
"We stop, we come back, we stop on the changeovers. I think this is a little bit dangerous for the body with these very heavy conditions."
Nadal and Sinner only got on court at 10:30pm after Diego Schwartzman and Diminic Thiem had taken five hours to decide their quarter-final.
They also had to wait for another women's last-eight tie to be completed after two others had kicked off the programme.
The sparse and shivering crowd that greeted them wore thick coats, scarves and hats.
"I don't know why they put five matches on Chatrier. It's a risk," added 34-year-old Nadal who finished his news conference at 2.10am.
Nadal will be playing in a 34th semi-final at the majors when he faces Schwartzman - he holds a 9-1 lead although the Argentine won their most recent clash in Rome on the eve of Roland Garros.
World No 75 Sinner, bidding to become the first man to make the semi-finals on debut since Nadal in 2005, was left to rue missed chances.
He led with breaks in both of the first two sets, even finding himself just two points away from taking the opener.
Nadal admitted he had been in a contest unlike his first four matches where he dropped just 23 games.
"It was very tough during the first two sets and especially at the end of the first.
"He was hitting the ball very hard and with the cold, the balls had less lift."
Sinner has been tipped to make the world top 10 next season, but said he is not looking too far ahead.
"I'm a person who looks not in the future and not in the past, always in the present," said the Italian who had seen off two seeded players to make the last-eight - 11th seed David Goffin and sixth-seeded Alexander Zverev, the US Open runner-up.
Argentine 12th seed Schwartzman defeated US Open champion and third seed Thiem in a five-hour epic to reach his first ever Grand Slam semi-final.
The 28-year-old Schwartzman triumphed 7-6 (7/1), 5-7, 6-7 (6/8), 7-6 (7/5), 6-2.
It was one marathon too many for Thiem, the runner-up in Paris for the last two years, who had needed five sets and three and a half hours to down world No 239 Hugo Gaston in the fourth round.
Schwartzman's success came on the same day that compatriot Nadia Podoroska, the world 131, reached the last-four of the women's singles.
"Dominic is one of the great players. He is my best friend and I have a lot of respect for him," said Schwartzman.
"So this win is very important for me. In the second and third sets, I was going a little crazy and I was screaming at myself because I had so many chances. But, come on, I deserved to win tonight."