So we can't get hypothermia? Agreed there will be a reduction in blood flow, but there will still be some warming up required. And I would imagine that the lon

So we can't get hypothermia? Agreed there will be a reduction in blood flow, but there will still be some warming up required. And I would imagine that the longer you're in the water, the longer you'll get cooling just from a pure conduction basis, irrespective of blood flow. Not saying that I buy the whole "You'll lose weight based on physics alone!" in so much that it'll be significant, but the effect will be non-zero.