Hypoxia (oxygen starvation) will lead first to unconsciousness then without oxygen, cardiac arrest and death is probably 2-3 minutes after the cabin atmosphere equals the 45,000’ pressure.
Essentially it’s a suffocation death. At least ya pass out first. You are trying to breathe, but it’s not doing any good.
Cabin heat is controlled separately from cockpit heat. The flight crew controls it from the flight deck. Same for the cargo hold. Cargo has been ruined and pets killed by crews who forget to maintain pressure and temp in the cargo hold.
Freezing would take a bit longer.