TOKYO -- French Open finalist Anastasia Pavlyuchenkova grasped for an air tube during a medical timeout and grew frustrated at the lack of ice in a court-side container.
Mona Barthel struggled with 10 double-faults in a loss to Iga Swiatek as a searing sun made it nearly impossible to see the ball once she tossed it.
Heat and humidity quickly became a major issue when the Olympic tennis tournament opened Saturday. The temperature soared to 91 degrees F (33 degrees C) and the heat index made it feel like 100 F (38 C).
"You're just not feeling great," Pavlyuchenkova said. "So I wasn't enjoying it at all."
Still, Pavlyuchenkova routed Sara Errani of Italy 6-0, 6-1.
Midway through the second set, though, doubts started to creep into Pavlyuchenkova's head as she shoved bags of ice up her skirt on a changeover. Then she had trouble fiddling with a tube blowing cold air next to her seat.
"It's not easy to find the right position because it's just on the bench and somebody has to hold it so the air is blowing on you," the Russian said. "I don't think it was well prepared."
Second-seeded Daniil Medvedev, who also competes for ROC at the Tokyo Games, called it "some of the worst" heat he has played in after eliminating Alexander Bublik of Kazakhstan 6-4, 7-6 (8).
"I'm not going to lie. But you have to play," Medvedev said. "That's the Olympics, you go for the medal. You are not here to cry about the heat."
Medvedev suggested that organizers move all matches to the evening to avoid the heat of the day.
"I don't think they are going to change anything in the middle of the tournament but that's what can be done," he said. "I think the fact that we have only one minute between the changeovers is a joke. ... It should be 1:30 like it is in other tournaments."
World No. 1 Novak Djokovic sided with Medvedev.
"I agree with him 100%," Djokovic said. "I actually asked as well. My team captain Viktor Troicki was speaking to the referee a couple of times.
"To be honest I don't understand why they don't start matches at say 3 pm. I heard for tennis there's some kind of curfew for them to finish by midnight. If that's the case I just finished the last match. It's not even 5pm.
"We still have like seven hours to play. They have the lights on all the courts, they're going to make life much easier for all of us players. I just don't understand why they don't move it, I sincerely don't understand."
Djokovic beat Hugo Dellien 6-2, 6-2 in his Olympic tournament opener. Djokovic is attempting to become the first man to complete a Golden Slam by winning all four major tennis tournaments and an Olympic singles gold medal in the same year.
Pavlyuchenkova also criticized organizers for not having enough ice in a court-side container.
"Every time I had to take the ice pack or ice towel it wasn't cold at all," she said. "The ice melted. ... I was surprised. They expected the heat and it wasn't 100% ready for us."
Pavlyuchenkova needed more than an hour after her match to recover before talking with reporters.
"I feel a bit better but I just have a massive headache now," she said. "I think they somehow could have tried to make it a bit easier."
Players wrapped towels filled with ice around their necks to cool down on changeovers. But on the court, there was no way to escape the sun and heat.
On one occasion, Barthel lost sight of the ball completely on her serve.
"I was blinded by the sun," the German player said. "I couldn't see it anymore."
There are rules for extreme heat that call for a 10-minute break between the second and third sets if players request it. Play can also be suspended if an internal advisory group deems conditions dangerous -- in which case play would continue on center court under a retractable roof.
While Swiatek also acknowledged how "hard" it was dealing with the heat, she seemed more pleased to extend a family legacy at the Olympics.
She grew up listening to stories from her father about competing at the 1988 Olympics in rowing, then won a bronze medal herself in doubles at the Summer Youth Olympics.
Swiatek beat the 172nd-ranked Barthel 6-2, 6-2 in the opening match on Center Court.
"It's just special playing for Poland and representing your country," said Swiatek, who became the first Polish player to win a Grand Slam title at last year's French Open.
Also advancing on the hard courts of the Ariake Tennis Park were Viktorija Golubic of Switzerland, Anna-Lena Friedsam of Germany and Nina Stojanovic of Serbia.
In men's action, 16th-seeded Alejandro Davidovich Fokina of Spain defeated Pedro Sousa of Portugal 6-3, 6-0 and John Millman of Australia eliminated Italian teenager Lorenzo Musetti 6-3, 6-4.
Golubic beat Maria Camila Osorio Serrano of Colombia 6-4, 6-1 and will next face either home favorite Naomi Osaka or Zheng Saisai of China.
The Osaka-Zheng match was originally scheduled to open play on center court but that encounter was moved to Sunday before Osaka lit the cauldron in Friday's opening ceremony.
Information from The Associated Press was used in this report.