What is an open fire in the following passage?

Question

What I am talking about here is not to be confused with doing science or studying science in the traditional sense. What I am talking about here is using what we know from science to improve our lives. We do that all the time and quite effortlessly, in fact even comfortably. For example, though it might be frigidly cold or torridly hot outside, we can create a comfortable environment within our home or our car by simply manipulating a device on the wall or on the dashboard that controls the environment to our liking. That is a wonderful option over heating our house with an open fire, or hitching up a team of horses to take us to our destination through the heat or the cold.

Answer 1

I assume it is referring to when fir pits used to be in the center of the room, with the smoke filtering out of a hole that was in the ceiling.

Also, it could be referring to a hearth (fireplace).

Answer 2

a fire place that doesnt have a glass door. You burn wood and the smoke goes up the chute of the chimney? its called open because...... it is open!