Tennis matches in Tokyo will have later start times starting on Thursday in a move aimed at protecting players amid extreme heat and humidity.
The International Tennis Federation says matches will start at 3 p.m. Matches had been starting at 11 a.m.
Several players struggled with heatstroke on Wednesday.
Daniil Medvedev nearly fainted during his win over Fabio Fognini while Paula Badosa left the court in a wheelchair after retiring from her quarterfinal match against Marketa Vondrousova.
The temperature rose to 88 degrees Fahrenheit, but the heat index made it feel like 99 degrees Fahrenheit.