Daniil Medvedev struggled to breathe in the Tokyo heat on Wednesday, asking the umpire who would be responsible if he died during his Olympic tennis match.
While he was able to finish his match, that was not the case for Spain’s Paula Badosa, who left hers in a wheelchair.
Organisers later announced that from Thursday start times for matches would be pushed back, which players including Medvedev had called for last week.
“I can finish the match but I can die,” Russian Medvedev told the umpire.
The 25-year-old world number two took a medical timeout on court and also had the trainer on during a 6-2 3-6 6-2 win over Italy’s Fabio Fognini that put him into the quarter-finals.
Chair umpire Carlos Ramos asked Medvedev if he was all right, with the second seed replying: “I’m fine. If I die, will the ITF [governing body the International Tennis Federation] take responsibility?”