The most obvious way around that would be some kind of cryoprotectant, but those have all proven very toxic so far. The next frontier would be trihalose, which we've figured out how to produce in quantity recently, so watch out for news on that. To get something hot evenly and quickly, RF heating works great, but it's not obvious there's any equivalent for cooling, unless you're dealing with a few already-cryogenic atoms. One thing I've wondered about is using high pressures that depress the freezing point of water, but those kinds of pressures are sometimes biochemically toxic on their own. No research on short exposure in animals seems to exists, unfortunately.

It's so close to working, I feel like we'll solve it eventually, but I don't know when or how.