Remember the grey bag that the electronic parts for a computer came in? Thats an anti-static bag.
Like ORAC says its not a big deal but if you have one around, use it. Otherwise just be careful and ground yourself before touching anything electronic, do not touch the circuit side of the hard drive and do not touch the terminals, both coming and going out of the freezer.
Then after walking back to the computer, touch something metal (like a desk frame) and the computer case before working on the unit. Those of us who work on computers from time to time have a wrist strap that clips onto the computer frame to ground ourselves.