Jannik Sinner crashed out of the French Open in the second round on Thursday after dramatically cramping, one game away from winning the match. The world No 1, and the overwhelming favourite to win the men’s singles title, was two sets and 5-1 to the good against Argentine player Juan Manuel Cerundolo, when he suffered a physical breakdown. Barely moving, Sinner eventually called for the trainer and said he “wanted to vomit.” The Italian continued, but won only two more games as Cerundolo completed one of the biggest shocks in Grand Slam history. It means Sinner’s dream of completing the Career Grand Slam at Roland Garros – having had three championship points in his historic final defeat against Carlos Alcaraz last year – is over for another year. He hinted afterwards he will now take a break and won’t compete until Wimbledon on 29 June. Yet what are the heat rules in place? And what did Sinner say afterwards?Does French Open have extreme weather rules in place? The answer is yes – but the conditions required for a change to the schedule were not reached on Thursday. The official policy states: “If the WBGT [Wet Bulb Globe Temperature – which takes into account temperature, humidity, wind speed, sun angle and cloud cover] hits 32.2C (90F), play is suspended… this activates around 100F.”There are two sensors at Roland Garros – one on Court Philippe-Chatrier and one on Court 14 – which monitor real-time temperatures. At the start of Sinner’s match, the temperature was 29C, before rising to around 32C later in the contest. If the WBGT hits 30.1C, a 10-minute rest period is allowed between the third and fourth sets of men’s matches. If it reaches 32C, play can be suspended. However, despite the hot conditions and Sinner’s struggles, the specific WBGT recording did not reach the required threshold on Thursday to change the standard routine and order of play. Jannik Sinner struggled in hot conditions on Thursday (AP)Interestingly, the warm weather policy has no mention of closing the roof, unlike at the Australian Open. On Wednesday, Novak Djokovic said of the policy: “It’s always a discussion. But then if you close one roof, then all of the others are playing, it’s not fair, also. “Why would you close the centre court and then everyone else has to be playing on the heat? I wouldn’t agree with that.”How does hot weather affect athletes?Dr Lindsey Hunt, of Precision Hydration, says there are numerous phases athletes will go through when adversely impacted by warm weather. “The first phase is too much heat storage,” she said. “If the sweat required to keep you cool is more than you can sweat, your body temperature will keep rising. “It’ll either lead to a leaky gut, and you start having gut bacteria, or leaking from the intestines into the bloodstream, high body temperatures, above 40c temperatures, which can be quite dangerous. “Then there’s dehydration; if you don’t bring up your fluid intake alongside the increased sweat loss in hotter conditions, you’re at high risk of dehydration, which has risks of nausea, high heart rate.”What did Sinner say afterwards? To his credit, Sinner did not place blame at the fault of tournament organisers and did not use the weather as an excuse. "It was warm, but not crazy warm,” the 24-year-old said. “I feel like it was quite OK to play. "It was nothing against the heat, nothing against the weather. It was just me today, but it happens."Sinner struggled to move after first experiencing pain in the third set (AP)Instead, Sinner explained that he felt ill earlier in the day. "I had no energy today. That can happen. Nobody is a robot," Sinner added."I woke up this morning, didn't feel very well and tried to keep points very short. In the beginning, I was hitting very clean, very good, and then I just hit a wall."I started feeling dizzy. Very low on energy. I tried to serve it out but I didn't have a lot of energy."Is the schedule to blame? Sinner won Masters 1000 events in Monte-Carlo, Madrid and Rome over the past six weeks – with the latter two events part of the new extended Masters series events, taking place over 10 days.Ex-British number one Tim Henman stated after Sinner’s loss that, in hindsight, the Italian should have skipped either Madrid or Rome. But Sinner disagreed: "If I don't play Madrid or Rome, maybe I come here and I still have a day like this where you feel sick. Looking back it's always tough.Sinner will not play again until Wimbledon (AP)"I won three tournaments on clay. Incredible results. Amazing streak I've had. In the beginning of the year, this is my main goal here. “A very early exit is not what I was looking for, but you also don't know if things would have changed if I would maybe skip Madrid and play only Rome."When will Sinner play next? While unconfirmed, Sinner hinted he will now take a break and won’t play until defending his Wimbledon title, with the 2026 Championships starting on 29 June. Sinner usually plays a grass court warm-up event at Halle in mid-June.“I won’t play any tournament on grass before, most likely,” he said in Paris. “Now I need really some time off, recover completely, also mentally, and then be ready to go again for Wimby.”