US Open organizers have expressed "regret" for the way French tennis player Alize Cornet was treated for briefly taking off her shirt on court.
In the sweltering heat at Flushing Meadows on Tuesday, Cornet took her top off after realizing she had put it on the wrong way during a 10-minute heat rule break between the second and third set against Sweden's Johanna Larsson.
Cornet, who had been running late getting back to the court, reacted with surprise when she was then handed a code violation by chair umpire Christian Rask.
The incident led to a storm of criticism on social media, with Judy Murray, a former tennis coach and also the mother British star Andy, questioning whether double standards were at work for men and women.
"Alize Cornet came back to court after 10 minute heat break," tweeted Murray. "Had her fresh shirt on back to front. Changed at back of court. Got a code violation. Unsportsmanlike conduct ... But the men can change shirts on court."
The women's WTA tour was also critical of the incident, saying in an emailed statement: "Alize did nothing wrong."
"We regret that a Code Violation was assessed to Ms. Cornet yesterday," said the United States Tennis Association in a statement sent to CNN Sport.
"We have clarified the policy to ensure this will not happen moving forward. Fortunately, she was only assessed a warning with no further penalty or fine.
"Female players, if they choose, may also change their shirts in a more private location close to the court, when available. They will not be assessed a bathroom break in this circumstance."
Earlier Wednesday, USTA spokesman Chris Widmaier told CNN by phone that Cornet was given a code violation for "changing her shirt at the baseline. That was considered unprofessional conduct ... Basically that was a warning and there was no further penalty and there was no fine."
In the case of Cornet, Widmaier said the USTA had been following the rules of both the men's and women's Tours.
"As it relates to female players changing their shirts on court, they will have the right to do so as long as it is when they are sitting in the chair," said Widmaier. "We don't want people changing their attire in the middle of the court."
He added: "Also, in many of our stadiums and other areas, there are places very close to the court, where if the player wants to quickly move to a more private area to change her attire because of these pretty severe weather conditions, we will allow that, and not consider that a change of attire or bathroom break."
Under WTA rules, the women are given two bathroom breaks during their matches.
"So we don't want to be unduly harsh considering what the severe weather conditions are," said Widmaier. "If that player were to decide she would like a little bit more privacy, she will be able to go right off, adjacent to the court, to change and that will not be considered a bathroom break."
Still, the WTA called the code violation "unfair and it was not based on a WTA rule, as the WTA has no rule against a change of attire on court."
It added the code violation "came under the Grand Slam rules and we are pleased to see the USTA has now changed this policy."
The rule was also news to most former players and analysts.
Pam Shriver, a US Open finalist in 1978 and ESPN commentator and analyst, tweeted: "I found out tonight from the ref the rule @usopen for women to change shirts on court has been a code violation for years ... I did not know that ... In my day Barbara Potter did it often, I did it a few times. How about another rule "change?"
After slumping to a three-set defeat, during which Cornet cried and told the on-court doctor she needed to vomit and felt pain in her head and bones, the 28-year-old French star said the conditions had been a "nightmare."
Temperatures are set to rise to as high as 93.2F (34 degrees Celsius) on Wednesday in New York, with the US Open's Extreme Heat Policy in effect for both men and women for a second straight day.
Earlier this year, Cornet also suffered with the heat during her third-round defeat by Elise Mertens at the Australian Open.
"But still, you know, playing in this condition is of course very dangerous for the health of the player," Cornet told reporters.
"The limit of not playing the match is really high, it's like it needs to be above 45 degrees and humidity."