CANBERRA, Australia - Dozens of wildfires sparked by lightning strikes overnight were raging in heat wave conditions across rural southern Australia on Wednesday.

Firefighters were able to contain most of the fires in South Australia and Victoria. But authorities warned of worsening fire conditions on Friday, when winds were expected to gather pace.

South Australia fire official Leigh Miller said the number of fires peaked at 350 in that state since Tuesday, most of them sparked by lightning strikes. Lighting had also started 256 blazes across Victoria by early Wednesday, state Fire Commissioner Craig Lapsley said.

There were few reported injuries so far. In South Australia state, a woman sustained burns to her hands Tuesday while trying to save her home in Rockleigh, a health department official said on condition of anonymity, citing department policy. She was taken to hospital for treatment and discharged Wednesday.

In neighbouring Victoria state, 10 firefighters received medical treatment for heat exhaustion, fire official Jason Leigh said. There were no immediate reports of property damage.

A least 14 fires continued to burn across South Australia on Wednesday, Miller said. The number of fires across Victoria had been cut to 29 on Wednesday, with 16 burning out of control, fire official Mick Harris said.

Wednesday was the second day of a four-day heat wave forecast across southeast Australia, after temperatures reached 45 degrees Celsius (113 Fahrenheit) Tuesday in the South Australian capital Adelaide, close to the city's record 46.1 degrees Celsius (115 F) set in 1939.

Temperatures were expected to come close to 45 degrees Celsius across parts of South Australia and Victoria on Wednesday.

Lapsley said low winds had helped fire fighters contain the blazes Wednesday. But the winds would gather pace by Friday.

But Lapsley said conditions Friday would still not be as bad as the catastrophic conditions on Feb. 7, 2009, when wildfires killed 173 people and destroyed more than 2,000 homes in Victoria.

"It's not to say that we won't have fires and we won't have fires that do damage — that potential is there," Lapsley said. "But it's not the same in speed. It's not the same forecast."

Scorching temperatures at the Australian Open tennis tournament in the Victorian capital Melbourne on Wednesday thinned crowds at Melbourne Park and prompted players to pile bags of ice on their heads and necks between points.

Also Wednesday, residents were returning to their homes in southwest Australia after heat wave conditions on west coast over the weekend contributed to a fire that destroyed 52 houses in hills east of Perth. One man died while fighting the fire.

Authorities said that fire began when a fallen power line sparked a grass fire.

News from © The Associated Press, 2014