British number two Heather Watson has withdrawn from her first-round match in Istanbul after feeling unwell.
The 28-year-old took a medical timeout when trailing 3-2 in the first set against Spain's Sara Sorribes Tormo before deciding not to continue.
The Briton, who had her blood pressure and temperature taken, was the fifth seed at the TEB BNP Paribas Tennis Championship in the Turkish city.
Watson lost to compatriot Johanna Konta in the US Open first round last week.