Britain's Harriet Dart said she felt "under the weather" as she struggled in the heat during her second-round loss to Marie Bouzkova at the US Open. Dart struggled for rhythm in a 6-2 6-2 defeat by Czech 25th seed Bouzkova as temperatures reached around 30C in New York.

Dart's defeat means Fran Jones is the last remaining Briton in either singles draw at Flushing Meadows. Jones faces American 14th seed Iva Jovic later on Thursday. Dart draped ice towels around her neck and used cold-air hoses at the changeovers against Bouzkova as she attempted to cool down.

"I have been a bit under the weather. It is what it is, sadly," Dart, 30, said. "It was quite warm. I had a temperature, I was trying to cool down. I've played many weeks in a row. I am not used to air conditioning being pumped everywhere. We go from really hot outside to freezing inside. All credit to my opponent, she is an incredibly tough player, so even if I had been at full capacity, I don't know."

Dart, who is ranked 131st in the world, struggled on serve against Bouzkova, committing eight double faults and landing only 45% of her first serves. Bouzkova took command almost straight away, winning seven games in a row to clinch the first set and go a double break up in the second. From there Dart was unable to recover as Bouzkova safely saw out the rest of the match to reach the third round, where she will face Polish eighth seed Iga Swiatek.