Re: what are signs of cold weather damage?
As mentioned, fast extreme changes in temperature are bad for finishes, especially nitro.
But the biggest enemy is dryness, especially for acoustics though it can make frets sprout on electrics too.
I'm pretty careful to keep my acoustics well humidifed. And I keep a slightly damp sponge in the case with each electric.
Been doing that since the 70s when my friend Darrell Gilbert recommended it to me.