For this kind of thing, my go-to (now that I’m hacking the system and got to learning its innards but more intently) is the Zealot skill.
“Ignores best die” is POWERFUL, more than you realize in most cases. Another possibliity (and a cruel one at that) is draining RESOLVE, chipping away at resources that could come in handy afterwards.
Straight up narrative effects are also a good call - “you begin choking, coughing and coughing endessly as air flees your body and the smog enters it, you better get out of there fast!” and dropping a timer is a GREAT pressure push on the players that lights a fire under their butts to act.
There are many options, most of which are completely up to you. Experiment with these, or some others you come up with (“can they use Sharpshot as they shiver violently in the icy cold?”) and have fun with your players. That’s the most important thing.