As of now the blacksmith apron doesn't have any properties and is just for the looks, however i think that it would be nice to have some actual heat resistance stat.
It's my first winter in VS. I was doing some work in my forge, went to sleep and woke up nearly freezing to death because the forge/crucible heat basically destroyed my clothes durability. That made me to look for some ways to survive the rest of the winter, found the apron and saw that it doesn't have any heat resist property. I think that's a shame and would be really nice addition.
Maybe not like 100% resist but at least some. Or make it that it absorbs the heat, taking it's durability and eventually breaking before the heat starts doing damage to other clothes.