That first pool, don't they call it the Tub? My wife and I stayed overnight there one night after a storm had just gone through ( about 10 inches of snow on the ground ). Her brother lives in the town of Mammoth ( Lakes? ) and he told us the next day when we saw him that it had got down to minus 8 degrees that night in town. We had put my wifes down mummy bag inside of mine and then we both slept together inside both bags just to stay warm. It was a very cold night but we had a great soak in the morning enjoying the beautiful snow covered scenery :-)