Or something unexpected? The only time it happened to me was when my electrics went off while I was away. I was hot and tired, it was early evening and I knew there was a cold tin of lager waiting for me in the fridge. Couldn't wait. However, I opened the front door to the most horrendous smell. I would say the freezer had been off for the nearly 2 weeks I had been away. I spent the rest of the evening disposing of rotten food and the pool of mouldering blood and gunk in the bottom of the freezer.
I always think of that (now very old) episode of 'One foot in the grave', where they come back to find their house had burnt down. I always breathe a sigh of relief when I see ours is still in one piece, and can't relax until we've had a good check round. (That might be just me though being a bit of a worrier).