They may sound odd, but there's a few unconventional methods of getting a HD to spin up so that you can recover lost data. One of the most common methods I've seen is sticking the HD in the freezer for a little while, if you're having a problem with overheating this will at least give you some time to access the drive before it errors out again.

Last resort was to actually remove the hard drive cover and try spinning the platters manually with a soft object (qtip, felt, anything but your finger) and hoping it would catch and begin to spin at operating speed. Unfortunately this usually voids any warranty and you must work very fast as having an exposed drive doesn't leave you much time before dust and other things settle onto the platters. It's definitely not the safest method, but it has worked.