It's your yearly cleaning, Let's do a little research about this.
For me it's something I do every 6 months. But then again I see these things at 2 or so years and the dust and lint collections are amazing.
Have had this laptop for over a year and have been very happy with it. This evening the cooling fan came on and has not shut off for a couple of hours. I have spent all of this time trying to get system/device info to try to figure out what's going on (also spent fruitless efforts on backing up my hard drive...that's a separate issue (as in, user education required) but feels very compelling at the moment). Anyway, we've used the laptop today exactly the same as always, nothing odd with regard to operating conditions, types and amount of use, etc.