This year's Shanghai Masters saw several players, like Daniil Medvedev, struggle in sweltering conditions. Chen Haoming / Xinhua via Getty Images

The men's tennis circuit will introduce an extreme heat policy from the 2026 season, following player criticism during sweltering conditions at some tournaments this year.

Extreme heat and humidity at October's Shanghai Masters prompted Denmark's Holger Rune to ask during a medical timeout against Ugo Humbert of France: "Why doesn't the ATP have a heat rule? You want a player to die on the court?"

From next year, if the wet-bulb globe temperature (WBGT, which measures air temperature, humidity, and the impact of sunlight and wind) reaches or exceeds 86.1 degrees during the first two sets of a three-set match, either player will be able to request a 10-minute cooling break at the end of the second set.

If the WBGT reaches or exceeds 90 degrees, outdoor play will be suspended. This rule applies to ATP-run tournaments, and not the four Grand Slams, which set their own heat rules; the WTA has had a similar, unified policy to this new one from the ATP since 1992. Previously on the men's tour, on-site supervisors would make individual decisions from tournament to tournament and day to day.

Stifling heat defined this year's Shanghai Masters, in which world No. 2 Jannik Sinner succumbed to debilitating cramps against Tallon Griekspoor in the third round. Novak Djokovic vomited on court later the same day, during his win against Yannick Hanfmann, while Daniil Medvedev was so wary of cramping against Learner Tien in the fourth round that he even asked if a ball girl could remove his sweat-soaked shirt. A male ATP supervisor was on hand to perform the task.

In a statement following Rune's criticism, the tour had said that its lack of a mandatory heat policy was "under active review," with "additional measures, including the implementation of an official heat policy, are being evaluated in consultation with players, tournaments, and medical experts."

Such measures will now be in place for the start of next season in January.

Tennis heat rule will apply across ATP Tour from 2026 season after player criticism