I had a hard drive that's around 15 years old fail to start a couple of months ago--I tried many times with no luck. Most but not all of the stuff was backed up, but not all (though what wasn't backed up wasn't very important). So yesterday I stuck the drive in a freezer, in two freezer bags without much air. Today I plugged it into an IDE-USB adapter. It didn't start up at first, but after a few minutes of warming it up, it started and I got all the data off without any difficulty. This is the second time in my life that I've rescued data from an old hard drive using a freezer.
(Of course, there is always the chance that this time it would have worked without the freezer. I didn't actually check yesterday if the drive was still not working.)