>>1754792>How safe would it be to have an open fire in a shelter covered with debris?Really depends on the size of the fire and the distance from the walls and "ceiling".
Hot coals would be safest, but a Dakota Fire hole would probably work too with some forethought and planning. Also in winter you want to make your bed first before building the shelter over it.
Traditionally wigwams were covered with birch bark or skins and they've had campfires in them.