Yep it is inside a wood insert.
I do draw the line at rail road ties and tires.
My grandmother burned tires and she told me keep all windows and doors shut or you will have a lot of black soot in the house on everything.
All those old coots in my family lived past 93 years old.
First house I grew up in we heated our house with a wood burning stove. My dad burned old telephone poles and old cedar fence posts cause we were poor.