Dry conditions and wind Friday are causing concern for firefighters throughout Maine.

There have been a number of brush fires this week, including the most recent fire Thursday that threatened homes and injured a firefighter in Old Orchard Beach.

Fire officials say wind helped fuel the brush fire that spread across 5 acres. They’re still investigating to try and figure out what started it.

No homes were damaged, and the firefighter who suffered from exhaustion is expected to be OK.

Last Sunday, a grass fire in Wales burned about 100 feet of land when fire danger conditions were considered moderate.

On Friday, a Red Flags Warning from the National Weather Service will be in effect from 11 a.m. to 8 p.m. for many parts of the state. That means conditions are just right for fires to spread fast if they start because it’s so dry.

Firefighters say don’t burn without a permit and watch where you throw out cigarette butts, because sometimes that can cause a wildfire.