My guess would be that the .tmp files appeared because of an "untidy" installation of, or update to, Flash Player (which you need on your system in order to play videos from YouTube etc). If you delete the files successfully, I'd be happy with that and forget about it all.
If they reappear, you could try a "clean installation" of Flash Player over your existing one, which with any luck should solve the problem. How you'd do that installation would depend on your browser. I use Firefox but seem to remember you use something else. Anyway, here's the Adobe site:
Usual precautions apply: don't let it change your homepage or install stuff you don't want. And of course don't pay any money!
I used to know this stuff, but have forgotten most of it because these days such problems are fewer than with Windows XP - or going back further, Windows 98. Most things seem to happen automatically now, with less need for user intervention.