“The climb to 40,000+ feet points to two things, and two things only; either to kill the passengers or extinguish a fire”
If there is a fire, you do not climb. If anything, you don oxygen masks and make an emergency descent, looking for the nearest suitable airport.
““The climb to 40,000+ feet points to two things, and two things only; either to kill the passengers or extinguish a fire””
There is basically no oxygen at 35,000 feet. No need to go to 40,000.