Temperature is not it.
If you are getting lots of skipping, the fist thing you should check is your source material. Just because it plays fine in iTunes does NOT mean it should play normally on any iPod. iTunes is very forgiving of tracks that are in bad shape.
If your library is full of tracks that were created with ancient CD ripping tools, downloaded from the internet or just generally not encoded from a CD using iTunes or bought via iTunes, you should re-import that material.
In my case, I had a DVD drive that was on the edge of dying. I brought in a bunch of CD using it and they played fine in iTunes, but always seemed to cause problems on my iPod - skipping, just not playing, restarting the iPod. However, all of them played fine in iTunes. I finally figured out my DVD drive was bad, got a new one and after re-importing the offending tracks, everything worked fine.
Now this does not mean your DVD drive is bad. Some of the music I have been dragging around since the '90s and imported with tools from those days did the same thing.
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