From slightly freezy to FROZEN!

I remember sitting on the patio this summer and the only relief from the heat was putting our feet in our "pool." The pool is really part of my dismantled water feature from the last several years. I filled it up in the Spring mostly for Wilbur-the-cat-who-drinks-endless-water and the dog too. But one day it was SO hot it just seemed natural to take my ice tea outside, pull up a chair to the pool and, plop in my feet. It was quite refreshing. Well, now it is quite frozen. It had a few leaves in it and I was going to dump it out and lean it up against the fence before winter came. Then winter came with no warning....the temps just dropped and I didn't think it would last...and instead--it got colder. The dog and the cat (when he goes out-he is kind of a fair weather cat) are totally confused about the ice in their water source.