Locks only keep the honest folks out.
You haven't seen my Abloy PL 362 padlock. I admit the S&G 951C (one of the few locks kosher for securing nuclear weapons) has better liquid nitrogen protection, but I'd be willing to bet you'd break it after beating a couple dozen hippies to death with it. The Abloy padlock? You could beat every hippy ON THE PLANET to death with it, and it'd be fine after a thorough washing.
Yup, critical file backups, photos of stuff for insurance, etc. are on DVD or flash drive and stored in the fire rated gun safe (among other places physical and cloud).
One bad thing about fire safes is that their rating is for paper. Which is 'fine' up to around 300 degrees ish. Most media starts getting unhappy around 110-130 ish. Photos can be inbetween.
Naturally, for business purposes, I use these: http://www.turtlecase.com/tape-cases
Wanna know an even better solution, however? Throw your flash drives in a thermos.
Specifically, I recommend the Zojirushi line for best budget r value.
Better? Used Dewar flask from a lab.
Best? Used cryogenic liquid nitrogen tanks. An empty one, folks. Think normal Dewar flask on steroids.
Your fridge will have roughly equal performance to most fire safes, but be inferior to a proper high end fire safe. Regardless of fire safe quality, if it's small, store it in a container for better temperature regulation.