Nish Nayar, via Facebook asked:
Has any living organism ever been recovered back to life after freezing? What are the current problems we are facing in order to make this a reality?
Barry - Well, there are some lower vertebrates that have evolved to live in very cold parts of the world, the Arctic Tundra or Canadian Permafrost areas, and it seems that they have developed a system which allows them to make their own anti-freezes as winter turns around the corner. They're seasonally adjusted to make their anti-freezes and then they're able to survive freezing, but only freezing within a very limited temperature range of about minus 15 to minus 20 degrees centigrade. And they take very great care about where the ice forms in their body, so they are very carefully tuned to this process.