Hazards are present in all RPGs. Sometimes they will come in the form of traps that deal their damage, and then they are over and done with. Other times they will be a much more prominent obstacle, such as a pool of acid or massively over-leveled sentry, you need to completely avoid.
The noxious fumes are one such hazard. While you play Baldur’s Gate 3, you will receive the quest after your encounter with an NPC named Auntie Ethel.
What Are Noxious Fumes?
Noxious fumes are a hazard that will damage your party if they occupy the same area as it. You will encounter these noxious fumes in multiple parts of the game, including while you are making your way through the Overgrown Tunnel. You will be around the coordinates of X: -350 and Y: 550 when you see some of them. Normally you can use fire to transform the terrain hazard into an explosion and be done with them. However, this time they just reappear.
Disabling The Noxious Fumes
To get rid of the fumes in this area for good, you must first ensure your party is carrying around several crates and/or barrels. You will then separate your party members. Have whichever one of your companions with the highest Perception Checks move around the noxious fume clouds.
As they do, they will make several Perception Checks, and the ones that succeed will reveal hidden vents in these clouds of noxious fumes. You will then move the crates and barrels you brought with you to cover up these vents. Once all the vents in a cloud of these noxious fumes have something on top of them, they will no longer be able to fill that area with the noxious fumes, and it will disappear.
When You Cannot Reach
When you find that you cannot quite reach one of the vents, you can make use of various spells and cantrips, such as Mage Hand. Alternately, you can make a save, then enter turn-based mode to strategically put your party members in danger and then have them recover. There is a hard fight at the end, so be sure to have a long rest to get everyone back up to full health and recover all uses of their features.