#and maybe bakur's giant deity answered

[cxlandine]

the wind is cold and that is why for each other we light the campfire is beautiful.

and it has to be said that lucy was a frost genasi. it's a homebrew race, but logically it would make sense for her to be vulnerable to fire damage. lighting a campfire to melt away the cold could kill her - and i think it's very telling that she specified that we light the bonfires for each other. the rest of her party needed protection from the cold and she was the cold, maybe.