The second week of the United States Open has begun feeling a lot like the first one.
After a few days of relative relief, the sweltering weather returned, with temperatures reaching 90 degrees (more than 32 Celsius), and humidity climbing above 70 percent at the U.S.T.A. Billie Jean King National Tennis Center.
For the fourth time this tournament, the U.S.T.A. put its special heat rules in effect, allowing for 10-minute breaks after the second set of women’s and juniors matches and the third set of men’s matches. But those breaks could supply only so much relief.
On the Grandstand court, which offers less shade than the stadiums with retractable roofs, Lesia Tsurenko awaited divine intervention as she melted in the midafternoon heat in the first set of her fourth-round match against Marketa Vondrousova.