It's tough to say, all cards are a little different as to how much punishment they can take. I had an 8800GT that would flirt with 100c when overclocked and stressed, I've moved on from it since then but it still works fine after years of that. Are you noticing any performance issues from the heat?
Are you putting the laptop on a desk or similar surface where it can still draw in air? Leaving it on a bed is always going to cause overheating. If the laptop is old you can try to blow some compressed air through the vents and unclog dust from the heatsinks and fans.