My fan noise has been increasing the past week. Now I can't even watch a 1080p movie on my MBP 13" from last year without the fans spinning up to around 4000rpm. I know that's not a lot but it's more than it used to and during the movie I can hear the fan noise - and the MBP gets a little hot. Should I be concerned? Or maybe cleanse my fans? ---------- I run Lion as I haven't upgraded it to ML yet. EDIT: I'm now running ML but haven't checked if the fan noise is louder than usual.