Well if it makes you feel any better, stock bulbs burned at about 275 degrees F, Nokyas burned at about 310 degrees F (after being on for 10 minutes with the car parked). On this scale, it's not that big of a difference.
The bulbs I have are labled at 55W, and have caused no problems after two months of heavy usage.
My initial post on these bulbs:
Aftermarket Bulb Comparisons
Just trying to answer your question.