Effect of Mining on Hardware I've installed a mining client on My Macbook pro, which was giving almost 1 MHash/s at full capicity. I found on some reddit thread that Mining may affect the hardware i.e. mother board or graphic card and their lifespan.

So my question is what will the mining work do to my laptop's(or pc's) hardware? Will it burn it out? How can I optimize the machine to be Mining friendly?
I have a 2012 Macbook Pro mining Litecoins (CPU&amp;GPU at a combined 80kHash/s) and a 2011 iMac (71MHash/s on its HD5670) mining BTC. They both run overnight and on weekends, I turn the mining software off over the weekday. Doing this for months now. 

So far, there were no overheating problems, but i have an extra cooling stand for the Macbook, which i would recommend.

Still, I expect the hardware to die sooner. The heat management in Apple machines is very delicate because of the case design, and I heard of people waking up to a dead iMac.