Self test for fan function?

Hi

My Macbook's fan has started running a lot, kind of suddenly.

Now I live in Thailand, the cold season's finishing, and it's not impossible it's the temperature (right now it's cooler at night and there's no fan). I have upgraded to 10.5 and a 320gb HD since last hot season so perhaps it uses more ooomph.

I wonder if there's a test procedure I can do to check things out.

thanx v much

Cheeryble

 

........in kind of leaf-blower mode....