After Novak Djokovic, Jannik Sinner & Co.'s complaints, ATP forced into new Heat Rule change for 2026

The weather was not great in Shanghai and some other ATP tournaments this year, leading to frustrations from the likes of Novak Djokovic and Jannik Sinner. During the 2025 Shanghai Masters, temperatures rose to above 30 °C with heavy moisture. Sinner retired mid-match due to severe cramping while the 24-time Grand Slam champion battled vomiting and exhaustion.

Apart from these two tennis stalwarts, Daniil Medvedev also suffered cramps against Learner Tien in the fourth round. Denmark's Holger Rune directly questioned the ATP for the heat rule.

“Why doesn’t the ATP have a heat rule? You want a player to die on the court?” Rune said. “There should be some kind of rule. We can handle a certain amount of heat because we are fit, strong and mentally strong as well, but there’s a limit. It’s also important to take care of your health. We need to survive.”

On Monday, the ATP finally addressed those complaints around the heat rule, which was not consistent between Grand Slam and other ATP tour events. The ATP board has introduced a new heat rule starting from the 2026 season. The new policy is based on the Wet Bulb Globe Temperature (WBGT) and ensures cooler measures, especially for best-of-three singles matches.

As per the new policy, if the WBGT reaches 30.1°C or higher during the first two sets, a 10-minute cooling break can be requested by either player. Players can hydrate themselves, change their clothes and also take a shower during this break. Moreover, play will be suspended if the temperature spikes beyond 32.2°C.

What was previous heat rule in ATP that made conditions terrible for Jannik Sinner & Co.?

Before this new policy came into place, the ATP outside of Grand Slam events let the on-site supervisors and medical staff decide if the conditions were extreme enough to force a stoppage in play. As such, there was no universal rule in play, leading to ambiguity among players and supervisors.

However, the Grand Slam events had a long-standing Extreme Heat Policy (EHP), according to which, if the WBGT crossed a danger threshold, matches could be delayed or even suspended. Especially in Australia, where conditions can be terrible in Melbourne, such a rule has resulted in match delays and suspensions. The US Open has also sometimes made use of this rule for the betterment of players.

Now, it seems other tournaments, especially those in Asia, will also have to follow.