The ATP are considering a major rule change following a scary incident involving Jannik Sinner.
The world number two was forced to retire mid-match during his latest game at the Shanghai Masters.
Sinner ended the fourth game of the third set crouched over in pain, before being helped back to his chair.
The Italian ultimately decided to retire from the match while trailing 7-6 (7-3) 5-7 2-3.
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He is just one of several players struggling with the brutal conditions in Shanghai, where temperatures have exceeded 30C and humidity has reached 80%. The extreme weather conditions has drawn criticism from leading ATP tour players, including Novak Djokovic and Holger Rune.
World number 11 Rune questioned why the ATP does not have a heat rule in place for tournaments outside of the Grand Slams.
At major competitions, a heat rule can allow matches to be suspended or give players longer breaks to recover.
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It has been used primarily for the Australian Open, which also operate a heat stress scale to measure the impact of conditions on players.
On the WTA Tour, women are offered a 10-minute break once the Heat Stress index reaches a certain limit.
An ATP statement said: "This remains under active review and additional measures including the implementation of an official heat policy are currently being evaluated in consultation with players, tournaments, and medical experts. Player safety remains a top priority for the ATP."
Former world number one Djokovic is also likely to welcome the introduction of a heat rule.
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The Serbian struggled with the conditions during his round of 32 victory over Yannick Hanfmann, even vomiting during the match.
He again struggled in the last 16 against Jaume Munar, falling to the floor following a long rally in the second set, before medical staff checked his blood pressure.
Despite the challenges, he returned to the court to reach the quarter-finals, where he will face Zizou Bergs.
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After his 6-3 5-7 6-2 victory over Munar, Djokovic said: "It's same for every player out on the court, but it's brutal.
"It's brutal when you have over 80 per cent of humidity day after day, particularly for the guys when they're playing during the day with heat, with sun, it's even more brutal.
"For me, biologically it's a bit more challenging to deal with it. But I had to really weather the storm today.
"Yannick played an incredible match from the beginning."
Topics: Tennis, Jannik Sinner, Novak Djokovic
James Taylor