Australian emergency services were bracing against "potentially catastrophic" fire conditions on Saturday as firefighters battled nearly 50 blazes in the state of New South Wales, sweltering in a heat wave sweeping the country's east coast.

Weather officials fear temperatures could hit 48 degrees Celsius (118.4 Fahrenheit) in some areas, setting a record for the state's hottest February day ever. People have been banned from setting fires, and some major sports events have been cancelled.

"It's not just another summer's day. This is as bad as it gets," Shane Fitzimmons, rural fire chief in the state, which was already battling 49 bush or grass fires by midafternoon, told reporters.