If your working your laptop to its full capabilities then you might get higher temperatures. If its only normal use then a clean of the vents and fan may be needed.
It is resting on a flat surface with a gap underneath isn't it?
The fan on mine is on all the time, working or idle. The only time it stops is when the laptop is turned off or I put it into sleep (or similar) mode. How do I clean the fan (assuming that's what is required)?