They're united for Team Switzerland in Davis Cup play, but divided about the heat.

Roger Federer railed against the handful of players that retired from this year's U.S. Open over heat-related issues, Sporting News reported.

Non-Coach Jimmy Connors Helps Eugenie Bouchard Before U.S. Open

Federer's comments differed from that of fellow Swiss player Stan Wawrinka, who made his case that the men's side is subject to greater exposure to heat-related issues.

Stan Wawrinka's Girlfriend Livid At ATP For Not Suspending Nick Kyrgios

"We've been here in North America for some time," Federer told reporters. "It's not like, all of a sudden, hot.

"I mean, it was more on the warmer side, but it's not like impossible, to be quite honest. Really no excuse for that. I think everybody should be well-prepared. I know we don't play many best-of-five-set matches all the time, so of course the body can react funny once you exceed the two-and-a-half to three-and-a-half hours of play. Maybe some guys already came in too tired, whatever it was."

Of course, the second-ranked Federer spent just two hours and 39 minutes on the court in total during his first two matches in New York, where temperatures have been in the 90s. Wawrinka, like Federer, has won his first two matches without losing a set. However, he has spent 5:24 on the court, more than double the time Federer has spent playing.

That may explain the No. 5 seed's differing opinion on the heat. He noted that the WTA allows women's players a 10-minute break between the second and third sets and believes the men should be afforded the same opportunity if the heat and humidity reach a certain level.

"We can be better physically, maybe, first thing to do," Wawrinka said, according to Tennis.com. "That's just a question I always [ask] myself. Why they have the heat rule if it's dangerous [for WTA players] after two sets to have 10 minutes and why [ATP players] don't have anything for five sets that's maybe there.

"That is the question, if we want to see something for the guys. But, again, in general, I think this year especially with so many retirements in general."

For more content, follow us on Twitter @SportsWN or LIKE US on Facebook