There are never any files in the Temp folder that are necessary for
Windows to run. Unless an install is in process, any files in the Temp
folder may be deleted. However, there are likely a few that cannot be
deleted because they're in use. While it's safe to empty the Temp folder,
it's not a good idea to erase the folder itself. If you do that, some
programs may not work correctly.
All this presumes the the original poster really meant the Windows Temp
folder and not the Temporary Internet Files folder, which would
actually have been on topic in this group. Anything in the TIF is safe to
delete at any time, but the preferred way to do that is through INternat
Options.