NEW YORK (AP) — The Latest on the U.S. Open tennis tournament (all times local):

11:25 a.m.

Play at the U.S. Open is beginning under an extreme heat policy and it will remain in effect until further notice.

The women's tour has a heat rule that allows for breaks during singles matches because of the heat. The men's tour does not, but the policy was extended to the men on Tuesday when temperatures soared into the mid-90s. They are expected to remain there Wednesday.

The WTA Tour rule permits a 10-minute break between the second and third sets if either player requests it. The men's break would come between the third and fourth sets.

A statement from the U.S. Tennis Association says appropriate medical timeouts for heat-related illness also are allowed.

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11:05 a.m.

Venus and Serena Williams can set up their earliest Grand Slam meeting in 20 years if both win second-round matches at the U.S. Open on Wednesday.

Venus has an afternoon match on another hot day in Flushing Meadows against Camila Giorgi. Serena, at No. 17 seeded one spot below her older sister, should face cooler conditions during a night match against Carina Witthoeft.

If both siblings win, their third-round matchup would be their earliest at a Grand Slam tournament since they played in the second round of the 1998 Australian Open in their very first meeting on tour.

Temperatures were expected to be in the mid-90s, as high as or even a little warmer than Tuesday, when six men retired from their matches.

Defending champions Rafael Nadal and Sloane Stephens also are in action, along with past champions Juan Martin del Potro and Andy Murray — who could meet in the third round.

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