Where are temporary files in Chrome stored?

"On Windows this is the Google Chrome cache folder:
%LocalAppData%\Google\Chrome\User Data\Default\Cache

However:
Google Chrome cache technique is defensive!

Although you could use YouTube
downloader program or manually
retrieve the YouTube video direct
download link to keep a copy of the
video for your mom who only likes to
watch them on the classic TV + player
set, you might need to use non-Google
Chrome web browsers to retrieve the
FLV files on some less popular video
hosting sites, via the web browser
cache folder technique.

Read this excellent post for some more info (though it might be outdated)"

"Depending on your configuration(s), Chrome may indeed store YouTube videos in the temp directory. However, they will be locked (i.e., cannot be opened or copied), as well as set so that they are automatically deleted when the lock is released (i.e., when the tab with the video is closed). You would need to first identify the correct file (this is easy if you observe the directory while the video is buffering because you can see the filesize growing). Then you can use Unlocker to save a copy of it.

Another, easier option is to simply use an extension like YousableTubeFix or YouTube Center."