Can I retrieve stuff from Outlook temp even if I have closed Outlook?

Folks, I think I must have re-worked a document sent to me as an attachement, but when I saved it with a new name I did not specify a folder on my hard drive for it to go into. I have done this before and now have a word document reminding me how to recover items fromm Outlook temp folder. But when I went there it was empty. I am thinking this may be because I closed Outlook at some point during the day. If so, does this mean the file is gone for good? Thanks, David