The old FX series did not have built in temp monitors afaik, so know program will tell you them temps. You could install a temperature monitor but it would probably not end up accurate any ways
If it isn't artifacting and running OK, I wouldn't be too worried about it, gfx cards just run hot. My 6800GT loads at ~60c and that is considered cool. Those 5200's could load at 90c, idk.
If you want to install a fan, that's not a big deal. Just buy a small fan that is about the size of the HS. A chipset fan might be about that size. Then just super glue it on there, or use zip ties or something, and plug the fan into the psu.