Tymoshenko informed President Viktor Yanukovych in an open letter Tuesday that she would not go back to her room at the hospital while she is watched by security cameras, the Russian RIA Novosti news agency reported. She has also said she will not go to court.
Andriy Lapinskyi, an official with the state prison service, said at a news conference there was a cot in the shower room, the Ukrainian Unian news agency reported. He said hospital staffers provided Tymoshenko with a blanket.
"Firstly, she was sitting in a corridor. And for the night she moved to a shower room and spent a night there," he said.
Tymoshenko, 52, was sentenced to seven years in prison for abuse of office for a 2009 gas agreement with Russia. Members of her Batkyvshchyna or Fatherland Party say the trial and conviction were political.
She has been hospitalized in Ukrzaliznytsya Hospital in Kharkov because of health problems.
Tymoshenko has engaged in other acts of civil disobedience during her imprisonment including two hunger strikes.