Freezing isn't considered humane in professional circles. There was a study done about this several years ago and one of the primary participants, Dr. Adolf Maas, gave me the following response to sum it up when I asked him about the study:
"Cooling does produce torpor, as I stated, but they are not unaware.
EEGs will show that there is still normal brain waves. That's not a coma,
just immobilized. Take a look at the function of a drug called
succinylcholine and the immobilization it produces- normal pain reception, normal brain function, all other sensory function normal, but unable to move and limp. That's why it's now immoral to use for surgery (they used to!)."
This was from an older thread that you could probably still dig up if you wanted to search back in history.