I can confirm, that you can instantly die by lava if you go to the forge, even if you stay on the iron grate. Especially if you go over the iron bars between the steps and the grate you may die. Furthermore i noticed, that my corps may vanish in this area, even if i make it in time. For example, i died next to a lava stream, but placed a bedroll nearby to retrief my gear if i die. Yet it was all gone due to my body vanished. Same goes for the incident at the forge. Could this be because of the lava itself? Lost top gear, including legendary weapons, because of this.