they are "supposed" to take it. I don't think it is really too hot for these chips. But I do believe nVidia is pushing them a bit too far. My 7950GT usually ran at 90-95 degrees full load with thermal protection kicking in at 130! It died within 2 years. I will never be sure it was these temps that killed it but I suspect it.
AT tested a fanless 8800GT that got over 100. It was supposed to take that aswell but I wonder for how long...
I believe these temps do really shorten the lives of these cards, though.
I have a TNT that still works,
a TNT2 that runs in a friends computer,
a 9700 Pro that I physically killed (would otherwise still be fine),
a Viper 440 that is still fine,
a Ti4400 running at Ti4600 speeds but still OK,
a 9800 Pro that I recently gave away (still fine)
a Ti200 at Ti500 speeds still running smooth.
However, my 6800GT died after barely two years (never OC'd) and my 7950GT is dead too.
So maybe getting an good aftermarket cooler could be a good idea when you want to use it for a long time.
You can also check with GPU-Z if your fan run at the proper speed. nVidia has a huge problem there with fans running at close to idle impervious to rising core temps.