MEERS, Okla. (AP) — A firefighter suffered heat exhaustion while helping crews battle a blaze that charred hundreds of acres in southwestern Oklahoma.

Comanche County spokesman Chris Killmer said Monday the firefighter was treated at the scene and released. There were no other reports of injuries or of property damage with the blaze, which Killmer says officials estimate burned 300 to 400 acres near Meers.

Killmer says the fire started about 6 p.m. Sunday and threatened 25 structures. He says crews from Meers and other agencies contained the fire Monday morning and were monitoring hotspots Monday afternoon.

The National Weather Service has issued a red flag fire warning for at least 11 counties in western Oklahoma until Monday night.