I don't get it. Without oxygen, the time of useful consciousness (TUC) at 35000 feet is 30-60 seconds according to this table:
https://en.wikipedia.org/wiki/Time_o..._consciousness

Alpinists spend weeks in successive camps to get acclimated to the altitude; these guys blow all handbooks about hypoxia. Plus, in 1862 gloves and hats had not been invented and used yet, right?

The difference is that you are applying science, facts and reality and Hollywood is not.
Some viewers may even argue that the balloon should have bounced off of the glass dome that is spanning the flat disc we live on!

Uli
'AS'