In order to do this you will need to pass through some poisonous gas, so you'll want to
bring healing items along with you.
Not exact matches
Usually they won't even
heal you unless other party members (including themselves) are below 50 % health so be sure to
bring a good amount of health
items to each mission.
You can make yourself a hot meal; find warmer clothes; build and light fires on the way up; or even just
bring enough
healing items along to brute force your way through.