It is very easy to have temp. files pile up, as you install and uninstall things. You can safely delete everything in the temp folder. You can also look for files with the ".tmp" extension and delete those as well.
Unless you have a install pending, just delete ALL the files, and folders in the temporary directory. Lazy programs leave their garbage to pile up in the temp directory, and it can grow out of control.
Anything left in the temp direcotry is GARBAGE.