It’s Thursday, Day 4 of the US Open. Players and fans have both braved the 90-plus degree heat this far on all of the courts at the Billie Jean King National Tennis Center in Flushing, Queens.

At times, the heat has surpassed 100 degrees and seems to be just as hot at night as its been during the day.

The USTA has instituted their Extreme Heat Policy for women’s and men’s singles matches until further notice.

The statement issued by the USTA reads, “For all women’s singles matches, a 10-minute break will be allowed between the second and third sets if either player requests such a break. For all men’s singles matches, a 10-minute break will be allowed between the third and fourth sets if either player requests such a break.” If both players decline, then play shall continue. Appropriate medical timeouts for heat-related illness are allowed.

Novak Djokovic, ranked sixth this season, and his opponent, Marton Fucsovics, took advantage if this policy Tuesday night, Day 2, taking an ice bath for a few minutes in the locker room to get some much-needed relief from the heat.

“I thought the 10-minute break was great,” said Novak Djokovic, “A much-needed break for both of us after playing two and a half hours, struggling.”

Djokovic won the match, 6-3, 3-6, 6-4 and 6-0.

Rafael Nadal, the defending champion, men’s singles, is ranked No. 1. Roger Federer is ranked No. 2. Kevin Anderson, who lost to Nadal in the finals last year, is ranked No 5. 

Gaël Monfils, 32, from France, now living in Switzerland, right handed, known for his trick shots on the courts, and Frances Tiafoe, 20, right handed, born in Maryland, living in Orlando, Fla. are players to watch. They both have advanced to play today (Thursday). Monfils plays Kei Nishikori from Japan. Tiafoe plays Australian Alex de Minaur.

Monfils turned pro in 2004, and Tiafoe turned pro in 2015. Monfils was a quarterfinalist in the 2016 Australian Open and a 2016 U.S. Open semifinalist.