I followed a huge header in the sky today which took me to a wildland prescribed burn in a nearby forest preserve. Firefighters with the Forest Preserve District of Cook County were conducting the burn for several reasons.
Depending on the vegetation present, these can burn fast and hot, producing thick smoke and tall flames.
The fires are started using a drip torch which allows the firefighters to safely introduce the flames in the burn area.
I have a video with highlights of the prescribed burn and more photos