A cold chamber can’t replicate everything a real expedition throws at gear, but it can isolate one variable at a time in a way a mountain never lets you — which is exactly what you need when you’re trying to find out whether it was the zipper pull or the zipper tape that failed at -35°C.
Every product that reaches a field test has already failed and been redesigned at least once in the chamber. The mountain is where we confirm the fix held, not where we discover the problem for the first time — that would be testing on the customer.