Hello everyone, I recently purchased a macbook to use in university. I have heard quite a bit about some of the heat problems that macbook have because they are plastic. Should I be concerned about the heat possibly damaging the components? Is it safe to leave the macbook on for long periods of time? What would be the mac amount of time you should leave it on for? Also, I use laptops quite a bit off my lap whilst lying in bed, watching TV, etc, is the heat bearable to do so? Cheers, Eric D.