just turn your house heat up to 74plus degrees and they'll be alirght!!! No tried and true answer for you from me, but I wouldn't think that if the temps were kept at about 68 degrees you'd be too bad, I wouldn't just throw them in the cold water, but let them acclimate, b/c it will be a traumatic time anyway. My two cents.
sorry had to edit some of my misspellings