British teenager Jack Draper was forced to retire from his debut on the ATP Tour after struggling with the heat and collapsing on court in the Miami Open.
Draper, 19, called for the doctor towards the end of the first set of his match against Kazakh Mikhail Kukushkin.
The Briton, who was trailing 6-5 on serve in hot conditions, was checked by the medic before deciding to continue.
Draper fell to the court as he chased a return on set point but was sat up with an ice pack on his neck moments later.
Medics quickly tended to the London-born player and he was able to walk off court.