Dick, Look for a DATA Safe, not a plain fire safe. Data (as in computer data) is moisture sensitive and not tolerant of high temps that ordinary documents could take. Acording to the lable the inside will be like a "normal" South East Texas summer day!

The lable says:

The product must maintain an interior temperature less than 125F and an interior relative humidity less than 80% for class 125, when exposed to fire as per the Standard Time Temperature Curve for 1-3 hours. It must undergo all other requirements for the Fire Endurance Test, the Explosion Hazard Test, the Humidity Test, and the Fire and Impact Test. Basically, no explosion through 30 minutes to exposure to a 2000F fire and immediate 30 foot drop test and a standard reheating for one hour to 1700F.