Vibrations, cooler and mac

I've just bought Belkin one-fan cooler to put under my MacBook Pro (sometimes it heats up a loooot).
michau wrote on :

HI, I've just bought Belkin one-fan cooler to put under my MacBook Pro (sometimes it heats up a loooot). It seems to work, but I noticed that the cooler slightly vibrates with high frequency and those vibrations transmmits onto the Mac. So I was wondering whether this can bring any kind of micro or macro damage to the machine? (Yeah I know this may sound stupid - if it does I apologize) Any sensible opinions on that?

Also when i'm at it, do you think there is a sense in using the cooler. I mean the bottom case heats up so much that it burns, but it's been always like that, so maybe that is what is suppose to be?

Thanks, Michal