A firefighter has undergone surgery for face and neck burns and a colleague is recovering in hospital, the NSW Rural Fire Service says.
Both firefighters were taken to hospital on Friday.
About 1000 firefighters are hoping to take advantage of cooler and calmer weather to contain the blazes across the Blue Mountains, Central Coast and Southern Highlands.
They are racing to get the upper hand on more than 80 bushfires in NSW. Sixteen of the fires are out of control.
Rural Fire Service Deputy Commissioner Rob Rogers described the mood among firefighters as "tired but determined".
"But they'll keep going," Mr Rogers said on Saturday.
"They've done this before. You just have to deal with whatever's dealt to us."About 200 fire fighters from Victoria, South Australia, Tasmania, the ACT and Queensland are also lending a hand to their NSW counterparts.