Loading "Roads and Maritime Services acknowledge water is a scarce resource at this time, however it is required to ensure the safety of motorists and keep the road open," a spokeswoman said in a statement. Meanwhile, the NSW Rural Fire Service was battling more than 50 fires across the state - 20 of them are uncontained. Deputy Commissioner Rob Rogers said 61 new fires were ignited on Wednesday alone, 31 of them started by lightning. "We're still trying to capture some of these fires and get them contained," he told 2GB radio.

Total fire bans were in place across much of central NSW, stretching from the Victorian border up to Queensland. Bureau of Meteorology forecaster Anita Pyne said the heatwave would continue into Friday with temperatures in the state's west set to peak in the mid-high 40s. While Sydney's CBD temperatures will be "moderated somewhat by effects of ocean and sea breeze", it is still forecast to hit a peak of 34 on Friday, Ms Pyne said. In Penrith, the mercury will soar to 45, "which is certainly very, very uncomfortable". Sydney is expected to feel the brunt of the heat on Friday as temperatures peak. Credit:BoM

The discomfort will be even worse in the state's far west with 48 the forecast maximum the Broken Hill and Menindee area, which is set to see four consecutive days over 45 for the first time since records began in 1959. In Canberra, there is potential for seeing four days in a row over 41 degrees, which has never been recorded before, Ms Pyne said. "Throughout NSW we are expecting it to be above average by quite a long way. Pretty much all of west of the Great Dividing Range are into the 40s," she said. "Night-time temperatures are still remaining quite warm, high-20s out in the west and the low-20s further east, making it quite difficult to sleep." Health advice: stay inside

Loading Richard Broome, director of environmental health at NSW Health, said people should limit their time outdoors, especially during the middle of the day. "Ozone levels are higher outdoors than indoors, and generally highest in the afternoon and early evening, so limiting time outdoors during the heat of the day and in the evening helps people to not only keep cool but to limit their exposure to ozone pollution," he said. Dr Broome said that hospitals across the state were preparing for a 14 per cent rise in emergency room admissions and a 13 per cent rise in mortality, after a similar event in 2011. There is particular concern for crowds heading to Tamworth for the weekend's annual Country Music Festival – especially those camping out in the sweltering heat. Daytime temperatures are forecast in the low 40s, while at night they won't fall below 20, she said.

Paramedics treated numerous patients for heat-related illnesses on Wednesday, including three children in the city's southwest who were suffering from exhaustion, heatstroke and vomiting. One was taken to Liverpool Hospital in a stable condition. Sydney rail commuters were being warned there could be delays across the network as temperatures rose. Air-conditioned trains scheduled for routine checks were returned to service, while extra maintenance and medical staff were on standby. Weekend change to bring 'comparative' relief