Bill Oertell wrote:

He seems to be doing fine now. But now my question his: should I put
him
back in the pond, after acclimating for several hours, or get an aquarium
for
him until the spring? The fish is going to have gone from 38 degrees to
something like 68 degrees and back in a little more than a day, and I'm
thinking that may be too much stress for the little guy.
Opinions are more than welcome. Thanks.

He'd probably have done best in the pond - which would have been harder for
you :-) Definitely don't try to put him back in the pond now. They can
handle a rise in temp much better than a drop.
--
derek