A lower temperature (as in a drop, not any particular temperature) generally means less wind and an increase in humidity, making life easier on the firefighters.
experiments don’t all have to be done at home or without regard to safety.
As you note, a fire-resistant safe can delay the time at which the contests reach a damaging temperature by a few hours. The post by Slithy Tove said “the economy of San Francisco was stalled” which certainly implies days.
Once the safe is cool enough to handle, opening it is more likely to decrease the internal temperature.
These guys apparently didn’t see the need for a regulator.
451 IIRC. 