Turns out, and you probably knew this, we've been doing this for awhile…not for space travel but in hospitals…patients are put into near-comas in order to allow them to rest and heal. We slow all functions down, brain, heart etc.
Now that same technology is being applied to space travel by NASA and a firm they are partnering with Spacewerks Enterprises to make it happen. You can read more here over Cnet, but it involves tubes up the nose to release the coolant, IVs to feed the space traveler and so forth.
The future is now and its here.
Just be careful what you dream . . .