Debbie,

Ajax Uploader automatically maintain this temp folder.  All temp files will be deleted. 

 

We compare the current time with the File.GetLastWriteTime.  Regular temp files will be deleted 5 minutes later. Persisted temp files will be deleted 360 minutes later.
 
After 360 minutes if some one uses the uploader, uploader will delete the expired files. If nobody uses the uploader,  the expired files will stay there.
 
If you have concerns abouy temp files, you can write some code and delete the temp files yourself.