New York - For Caroline Wozniacki, it was like "drinking a margarita on a beach" but for tearful Alize Cornet it was a "nightmare" as temperatures nudged towards the 40-degree mark at the US Open on Tuesday.
Four of eight early men's first round matches ended in retirements. Temperatures were expected to soar to 38 degrees by mid-afternoon, the effect made worse by suffocating humidity.
That may be short of the 41 degrees which remains New York's record temperature recorded in 1936 but that was little comfort for Italian qualifier Stefano Travaglia who retired at 6-2, 2-6, 7-6 (8/6), 3-0 down to Hubert Hurkacz of Poland.
"It was 36, 37 degrees but on court it was more," said the 26-year-old who quit with cramps but admitted "the first problem was the sun".
"To have 25 seconds between points in this weather is not possible.
"There was a lot of humidity, it was really tough. I hope that in my next tournament it will be less hot."
French player Cornet described the conditions as a "nightmare" as she slumped to a three-set loss to Johanna Larsson of Sweden.
Cornet, 28, wept as she sat courtside, telling doctors that she was ready to vomit and felt pain in her head and bones.
Cornet had already been hit with a code violation for changing her shirt on the court after putting it on the wrong way round during the "heat rule" break allowed by the WTA after two sets when the temperature goes beyond 30.1 degrees.
In response to the conditions, tournament organisers have allowed the men to opt for a similar 10-minute off-court rest at two sets to one.
"The tournament referee, along with the medical team, will continue to monitor on-site conditions, to determine when the Extreme Heat Policy will no longer be in effect," said a spokesman.
That came too late for Travaglia, Argentina's Leonardo Mayer, Ricardas Berankis of Lithuania and Romania's Marius Copil who all quit their first round matches.
Berankis's retirement was due to the heat, said the referee's office, while Copil had "an arm strain".
Copil had been 5-1 up in the first set on 2014 champion Marin Cilic on the Grandstand when he quit in the third set.
"The conditions were really difficult and it's tough on Marius. He really felt something," said seventh seed Cilic.
Australian Open champion and second seed Wozniacki dreamed her heat troubles away as she defeated 2011 champion Samantha Stosur 6-3, 6-2 on a sweltering Arthur Ashe Stadium.
"I just tried to cool down between games, used ice. I'm just thinking I'm on the beach, I have a margarita in hand, life is good," she said.
Two-time Wimbledon champion Petra Kvitova was just happy to finish her 6-4, 6-1 win over Yanina Wickmayer before the afternoon began to really cook.
"I was pretty lucky to play first on today, definitely. I knew it's going to be very hot, but I couldn't imagine how horrible the heat was," said the Czech.
Japan's Naomi Osaka couldn't understand what all the fuss was about.
"With this heat, everyone was complaining about it. So I thought it was pretty decent, like, Florida summers are way worse, I think," she said after beating Laura Siegemund of Germany 6-3, 6-2.
The heat and humidity had already been an issue on Monday when Stan Wawrinka, Kevin Anderson and David Ferrer all needed medical time outs.
So did Canadian teenager Flix Auger-Aliassime who quit his match against compatriot Denis Shapovalov after a worrying increase in his heart rate.
"That wasn't easy to see," said Shapovalov. "It's tough to keep pounding at it when he's a brother to me."
The United States national weather service says its heat advisory for New York City will remain in place until Wednesday night.
"The combination of hot temperatures and high humidity will combine to create a situation in which heat illnesses are possible," said the body.
US Open results on Tuesday, the second day of the 2018 tournament at Flushing Meadows (x denotes seeded player):
Marin Cilic (CRO x7) bt Marius Copil (ROM) 7-5, 6-1, 1-1 - retired
Hubert Hurkacz (POL) bt Stefano Travaglia (ITA) 6-2, 2-6, 7-6 (8/6), 3-0 - retired
Alex De Minaur (AUS) bt Taro Daniel (JPN) 6-0, 6-1, 6-2
Frances Tiafoe (USA) bt Adrian Mannarino (FRA x29) 6-1, 6-4, 4-6, 6-4
Julien Benneteau (FRA) bt Marco Cecchinato (ITA x22) 2-6, 7-6 (7/5), 6-3, 6-4
Jan-Lennard Struff (GER) bt Tim Smyczek (USA) 7-6 (7/2), 6-4, 6-3
Robin Haase (NED) bt Mackenzie McDonald (USA) 4-6, 4-6, 6-3, 6-1, 6-3
David Goffin (BEL x10) bt Federico Gaio (ITA) 6-2, 6-4, 7-6 (7/5)
Diego Schwartzman (ARG x13) bt Federico Delbonis (ARG) 6-2, 7-6 (8/6), 6-2
Jaume Munar (ESP) bt Ruben Bemelmans (BEL) 5-7, 6-3, 7-6 (7/3), 2-6, 6-1
Gael Monfils (FRA) bt Facundo Bagnis (ARG) 7-6 (7/4), 3-6, 6-0, 6-0
Kei Nishikori (JPN x21) bt Maximilian Marterer (GER) 6-2, 6-2, 6-3
Matthew Ebden (AUS) bt Filip Krajinovic (SRB x32) 7-6 (7/1), 6-7 (5/7), 4-6, 6-1, 4-1 - retired
Philipp Kohlschreiber (GER) bt Yannick Hanfmann (GER) 7-6 (7/3), 5-7, 6-4, 6-4
Nicolas Mahut (FRA) bt Corentin Moutet (FRA) 6-2, 7-5, 5-7, 6-4
Alexander Zverev (GER x4) bt Peter Polansky (CAN) 6-2, 6-1, 6-2
Novak Djokovic (SRB x6) bt Marton Fucsovics (HUN) 6-3, 3-6, 6-4, 6-0
Tennys Sandgren (USA) bt Viktor Troicki (SRB) 6-3, 6-4, 6-2
Laslo Djere (SRB) bt Leonardo Mayer (ARG) 6-4, 6-4, 4-6, 2-1 - retired
Richard Gasquet (FRA x26) bt Yuichi Sugita (JPN) 6-3, 6-1, 6-3
Lucas Pouille (FRA x17) bt Yannick Maden (GER) 7-6 (8/6), 6-2, 7-5
Marcos Baghdatis (CYP) bt Mikhail Youzhny (RUS) 6-4, 6-4, 2-6, 3-1 - retired
Joao Sousa (POR) bt Marcel Granollers (ESP) 6-2, 6-2, 6-3
Pablo Carreno-Busta (ESP x12) bt Malek Jaziri (TUN) 7-5, 6-2, 6-2
Fabio Fognini (ITA x14) bt Michael Mmoh (USA) 4-6, 6-2, 6-4, 7-6 (7/4)
John Millman (AUS) bt Jenson Brooksby (USA) 6-4, 6-2, 6-0
Mikhail Kukushkin (KAZ) bt Noah Rubin (USA) 6-3, 6-1, 4-6, 7-6 (7/3)
Chung Hyeon (KOR x23) bt Ricardas Berankis (LTU) 4-6, 7-6 (8/6), 6-0, 2-0 - retired
Nick Kyrgios (AUS x30) bt Radu Albot (MDA) 7-5, 2-6, 6-4, 6-2
Pierre-Hugues Herbert (FRA) bt Yuki Bhambri (IND) 6-3, 7-6 (7/3), 7-5
Benoit Paire (FRA) bt Dennis Novak (AUT) 7-6 (8/6), 3-6, 7-5, 7-6 (7/5)
Roger Federer (SUI x2) bt Yoshihito Nishioka (JPN) 6-2, 6-2, 6-4
Caroline Garcia (FRA x6) bt Johanna Konta (GBR) 6-2, 6-2
Monica Puig (PUR) bt Stefanie Voegele (SUI) 6-0, 6-0
Kristina Mladenovic (FRA) bt Tamara Zidansek (SLO) 6-0, 6-3
Carla Suarez Navarro (ESP x30) bt Nicole Gibbs (USA) 5-7, 6-3, 6-4
Maria Sharapova (RUS x22) bt Patty Schnyder (SUI) 6-2, 7-6 (8/6)
Sorana Cirstea (ROU) bt Alison Riske (USA) 6-3, 3-6, 7-5
Taylor Townsend (USA) bt Amanda Anisimova (USA) 3-6, 6-4, 6-3
Jelena Ostapenko (LAT x10) bt Andrea Petkovic (GER) 6-4, 4-6, 7-5
Madison Keys (USA x14) bt Pauline Parmentier (FRA) 6-4, 6-4
Bernarda Pera (USA) bt Yulia Putintseva (KAZ) 7-6 (8/6), 6-4
Aleksandra Krunic (SRB) bt Timea Bacsinszky (SUI) 6-2, 3-6, 6-0
Kirsten Flipkens (BEL) bt CoCo Vandeweghe (USA x24) 6-3, 7-6 (7/3)
Dominika Cibulkova (SVK x29) bt Arantxa Rus (NED) 4-6, 6-2, 6-3
Hsieh Su-Wei (TPE) bt Ekaterina Alexandrova (RUS) 6-3, 4-6, 6-3
Johanna Larsson (SWE) bt Alize Cornet (FRA) 4-6, 6-3, 6-2
Angelique Kerber (GER x4) bt Margarita Gasparyan (RUS) 7-6 (7/5), 6-3
Petra Kvitova (CZE x5) bt Yanina Wickmayer (BEL) 6-1, 6-4
Wang Yafan (CHN) bt Anna Karolina Schmiedlova (SVK) 6-1, 3-6, 6-4
Vera Zvonareva (RUS) bt Anna Blinkova (RUS) 6-2, 6-7 (6/8), 7-5
Aryna Sabalenka (BLR x26) bt Danielle Collins (USA) 6-0, 4-6, 6-4
Naomi Osaka (JPN x20) bt Laura Siegemund (GER) 6-3, 6-2
Julia Glushko (ISR) bt Monica Niculescu (ROU) 3-6, 7-5, 6-4
Aliaksandra Sasnovich (BLR) bt Belinda Bencic (SUI) 2-6, 6-1, 6-2
Darya Kasatkina (RUS x11) bt Timea Babos (HUN) 6-4, 5-7, 6-4
Kiki Bertens (NED x13) bt Kristyna Plyskova (CZE) 6-0, 7-5
Francesca Di Lorenzo (USA) bt Christina McHale (USA) 6-1, 7-6 (7/1)
Eugenie Bouchard (CAN) bt Harmony Tan (FRA) 6-3, 6-1
Marketa Vondrousova (CZE) bt Mona Barthel (GER) 6-1, 6-4
Katerina Siniakova (CZE) bt Anett Kontaveit (EST x28) 6-7 (3/7), 6-3, 7-5
Ajla Tomljanovic (AUS) bt Lizette Cabrera (AUS) 6-4, 6-1
Lesia Tsurenko (UKR) bt Alison Van Uytvanck (BEL) 6-3, 6-2
Caroline Wozniacki (DEN x2) bt Samantha Stosur (AUS) 6-3, 6-2