It was a historic day for interrupted tennis at the US Open.

For the first time ever at the tournament, men’s matches were paused following the third set for a 10-minute siesta due to the extreme weather conditions. Temperatures climbed into the mid-90s — with a real feel of 105 due to the humidity — in the middle of Day 2 on the scorching grounds at Flushing Meadows.

Unlike the women’s tour, which has set policy calling for a 10-minute break between the second and third sets when the temperature is above 86.2 degrees Fahrenheit (that’s converted from 30.1 degrees Celsius, don’t ask) at the start of the match, the men’s tour leaves it to the discretion of tournament officials. Starting around 1 p.m. on Tuesday, on the recommendation of the US Open medical team, the men were allowed a 10-minute break as well.

That didn’t prevent a few bodies from dropping. Ricardas Berankis of Lithuania retired in the fourth set of his match with a “heat illness,” according to tournament referee Brian Earley. Stefano Travaglia of Italy also trailed two sets to one when he retired due to “cramps.”

“Conditions definitely were extremely tough and very humid, very hot … very brutal,” said No. 7 seed Marin Cilic, whose opponent, Marius Copil, retired in the third set. “You know, that’s what makes it special for US Open, to play under this big humidity.”

The extreme heat policy for now remains strictly case by case and could be revoked on short notice if the atmosphere cools. It is expected to be in place during Wednesday’s day session as well, with temperatures forecasted in the mid-90s.

Players have the right to decline the heat break, if both wish to play on. Once the first player leaves the court, the 10-minute countdown begins, and players are responsible for returning on time. No coaching or medical treatment is permitted during the suspension.

“You have so many things to do on the changeover, drink fluids, gels, make sure your clothes aren’t too soaked,” unseeded American Tennys Sandgren said, “and try to recover in that period, it’s hard to eat anything, hard to keep calories in your body.”

Marton Fucsovics, who was run off the court by Novak Djokovic in the fourth set, regretted tightening up after taking an ice bath during his break. Andrea Petkovic, who lost a tight three-setter to No. 10 seed Jelena Ostapenko in the morning match at Louis Armstrong Stadium, felt an adverse psychological effect of retreating indoors.

“It felt hot, definitely,” Petkovic said. “Once I went in the air-conditioned room and came out, I felt like it was five billion degrees.”

Most players, many of whom are based in Florida, described versions of “it is what it is” and “it’s the same for both players.” No. 2 seed Caroline Wozniacki, an easy winner in the first match at Arthur Ashe Stadium, said she was “just about trying to think cool thoughts.”

“I think I was pretty lucky to play first on: It was pretty difficult conditions,” No. 5 Petra Kvitova said after opening the day session with a straight-set win. “It got hotter and hotter — and tougher. The ice towels helped a lot, of course. When you’re playing, you don’t think about it. When you stop for a while, you feel the heat, from the ground as well.”

There is no provision for closing the roof on Arthur Ashe Stadium or the newly domed Louis Armstrong due to extreme heat, though USTA communications director Chris Widmaier said it was being considered for Tuesday night’s session. The $150 million Armstrong is naturally ventilated, and does not have air conditioning.