It depends hugely on the laptop in question, as well as how new it is and the components involved. There are basically no laptops with adequate cooling, because there simply isn't enough room in the tiny little case to dissipate the heat as well as the designers would like to, which is why many laptops develop feel warm or even hot if you use them on your lap. There is no real way to say what is the normal temp. They are built to not melt themselves even under terrible conditions, so unless you did something specifically aggravating (overclocking, jabbing at the fans) then if the machine remains turned on then heat isn't a problem. It will likely limit your performance, as the chip throttles its speed to control temps, but if the worst comes to the worst it'll turn itself off to protect itself.