Yes, It is safe to delete those .tmp files. Prior to deleting them restart your computer then delete those .tmp files.
In doing some routine maintenance I came across some info that said to delete all temporary files in addition to Disk cleanup.
Follow these instructions:
Delete *tmp files - (temporary files)
*Start/Find/Files or Folders
*Search for files or Folders named *.tmp
*Look in: C:,D: etc.
*Once Files have been found you can delete them all.
I had to type in *.tmp for the file name, and the search found well over 500 TMP Files. Is it safe to delete all those files?.....it's never been done before and I've had this computer since Nov. 1998. I do run my Maintenance Wizard every 3-4 weeks.