Check out this article on how to wipe everything in firefox

How to clear the Firefox cache

And you may want to look into the Private Browsing feature

Private Browsing - Use Firefox without saving history

Thanks Anthony. I have been using Clear History before logging out of Firefox, but what I am wanting to do is to delete/shred these files fm my computer. I now in the background they are not deleted. I downloaded "File Shredder" fm the internet, but found that it only shreds deleted files and IE temp files. I am in search of a shredder that will shred Firefox temp files.........

Do you know where Firefox temp files are located? I do not see them under (C:)/Program Files/Mozell Firefox...........

Hope all is well down under, Mate!

Type about:cache in the Location (address) bar to see where the Cache you are using is located. Firefox does not use Temp files.

C:\Documents and Settings\<user name>\Application Data

Mine on Win7 is located in

C:\Users\anfcore\AppData\Roaming\Mozilla\Firefox