I looked up the etymology of scar...
late 14c., from Old French escare "scab" (Modern French escarre), from Late Latin eschara, from Greek eskhara "scab formed after a burn," literally "hearth, fireplace," of unknown origin. English sense probably influenced by Middle English skar (late 14c.) "crack, cut, incision," from Old Norse skarð, related to score (n.). Figurative sense attested from 1580s.
...and I found this text at a random site:
The word scar evolved from the Greek word eschara, meaning fireplace. Traditionally the fireplace was situated in the middle of the house and it was around this that most domestic activities took place.
It was the center of family life and an area where children gathered to be with family. As a result it was the location of many injuries, many of which resulted in scarring. In fact the injuries were so common that they became named after their cause.
> Traditionally the fireplace was situated in the middle of the house...
Is this information accurate? And if so - when?
> As a result [the fireplace] was the location of many injuries, many of which resulted in scarring.
Is this accurate?
I'm afraid I can't provide too specific of information as it's a very broad topic - but fireplaces have undergone a lot of transformations over human history. You do see a lot of them built into the walls of homes - they're more out of the way and can provide a major structural anchor to a house made of otherwise flimsier material. But there have been numerous times where this idea has been challenged. I'll do my best to answer from my experiences and study as an architect.
The first thing that came to my mind reading you question are early nomadic homes. These would tend to push a small fireplace to the center of the home because the home itself is made of lightweight, flammable material. The home would then be designed to funnel smoke up to a high point, which would vent out to keep the home from filling up. In colder climates I imagine it would be a bit of balancing act to keep enough warm air in and still let enough smoke out. A traditional teepee is an example of this type of construction, but there are a lot more if you look at different cultures.
The next idea is one which crops up in numerous architectural movements for one reason or another. The hearth tends to be a gathering point in a home, and so sometimes architect respond to this by making it a central feature. Frank Lloyd Wright was a proponent of this, for example. It comes from an examination of how people live their lives (people gather here for comfort, warmth, and cooking) overriding what may be considered an initially logical solution (putting the fireplace out of the way). Delving into this topic more would require a thesis level of research though, so unfortunately I'll need to leave it at that - but would be happy to answer questions people might have tomorrow.
As for the idea of injuries/scab - like rocketman said - etymologists may be able to provide more sources looking at that, but it sounds like an old wives' tale that has plausibility to it.
Try cross-posting to /r/etymology
So to answer the question at the end, yes, it is accurate. Before people had modern fireplaces with chimneys, they had open hearths. But the term 'hearth' is often preferred to 'fireplace' which implies a closed hearth built into a wall with a chimney.
Basically these hearthes were pits with stones around them that were placed in the middle of a room, with a hole in the roof above to let the smoke out, just like open hearths in various cultures today. In England at least they were common in peasant homes through the end of the 15th century, though they were replaced in castles and manor houses long before that.
I seem to have lost my copy of Barbara Hanawalt's "The Ties that Bound" but she goes into this in some detail. One consequence of the open hearths is that falling into fires was a relatively common form of accidental death for younger children.