“I don’t know how people don’t understand that,” said Pistorius, explaining that he was becoming emotional again because it was hard to talk about the events surrounding Steenkamp’s death.
Judge Thokozile Masipa had already asked him several times if he was tired, but he wanted to press on.
He returned to the witness stand looking less flushed about 10 minutes later, carrying a bottle of water.
Masipa checked in with him again and prosecutor Gerrie Nel carried on with the positioning of the fans.
Pistorius is on anti-depressants and a sleeping aid according to his earlier testimony and has been on trial since March 3.
Throughout the trial he has wept, howled, and vomited. Once, the court had to be adjourned because his shirt was wet with tears.
Before the trial, he was a super-fit international paralympic and Olympic athlete running on carbon-fibre prostheses after a double amputation as a child.
The State has alleged that he killed Steenkamp during a row, but he said he thought there was an intruder in his house when he fired into the toilet door and killed her.
Pistorius is also charged with three contraventions of the Firearms Control Act, one of illegal possession of ammunition and two of discharging a firearm in public.
He allegedly fired a shot from a Glock pistol under a table at a Johannesburg restaurant in January 2013. On September 30, 2012 he allegedly shot through the open sunroof of a car with his 9mm pistol while driving with friends in Modderfontein.
He has pleaded not guilty to all charges.