In this place resembling a tent, shadow man can be burned by a bonfire outside across the wall

what level are you talking about?

If I remember you can still get burned by the fire's until you get the final gad later on. This is not really a glitch though I do admit you should not get burned after marcher from walking on a fireplace. ( though strangely the dev's thought you should? I have no Idea why that makes sense)

Though I could be wrong? what level did you encounter the fire ,and what gad level do you have?