A cold front in northwestern Oklahoma brought increased wind speeds to an area enduring sweltering temperatures.
"It makes for a pretty nasty fire weather scenario," Austin said.
The wildfires posed special challenges for firefighters, many of whom were getting little sleep. Supervisors were closely watching their crews in the searing, wind-fed heat.
"They can only fight minutes at a time, come out to drink some water and go back in," said Capt. John Conkling of the Bristow Fire Department, which is helping combat the Creek County blaze near Freedom Hill. "Within 15 minutes your socks are squishing wet," from perspiration, he said.
Officials have described the Creek County blaze as the biggest threat.
With winds at about 30 miles per hour and a temperature of about 107, the strategy Saturday was to protect homes, he said. "To fight this fire offensively would be dangerous." Still, homes were lost Friday and Saturday.
"You want to try to help people and do the best that you can," Conkling said. "Sometimes you have to pull people back and say we can't do this because it is too dangerous."
Conkling said a couple firefighters were treated for heat exhaustion.
Seven firefighters suffered heat-related injuries Friday in Luther, northeast of Oklahoma City, said Lojka. One of them and a trooper were transported to a hospital for treatment.
David Richardson, spokesman for the Midwest City Fire Department in suburban Oklahoma City, said many crews are using lighter-weight and specialty gear in the wildfires.
"You've got to rotate those guys out," he said. "You have to look out for their safety."
Regan Siler, wife of Bristow firefighter Mike Siler, said Facebook and other forms of social media are getting the word out to communities about how to help neighbors and fire victims.
Residents across the affected areas also were donating snacks, water and Gatorade to fire crews.
"Everybody has come together to try to help," said Regan Siler. "So many of our friends have lost their homes."