Russian tennis Olympian Daniil Medvedev got so hot during his match on Wednesday that he asked the umpire who would be responsible for his death if he keeled over. The stifling heat has been a concern as athletes struggle to compete in the extreme conditions. Medvedev and superstar Novak Djokovic had pleaded with the International Tennis Federation to start the matches later in the day to avoid midday sun, but they were instead granted 10-minute breaks between the second and third sets, as set forth in the Summer Games’ extreme-heat policy.

“Even from the first set I didn’t feel good enough with my breathing. That’s why I called the physio—I felt like my diaphragm was blocked,” Medvedev said after using his 10-minute break for a cold shower, according to the BBC. “And then on the second set, I just had darkness in my eyes, like between every point. I didn’t know what to do to feel better. Like I was bending over and I couldn’t get my breath together so I was ready to just fall down on the court.” At a certain point, the umpire asked if he was OK. “I can finish the match, but I can die,” he responded. “I’m fine. If I die, will the ITF take responsibility?”

Medvedev is not the only athlete having a difficult time in Tokyo’s brutal heat and humidity. Spanish tennis player Paula Badosa had to leave her match in a wheelchair after suffering heat stroke. “It’s a shame to end my participation in this way,” she told reporters. “It’s been a tough ask since day one. We tried to adapt as best we could but today my body hasn't held up as it needed to.”