Yes, that's what I meant, sorry for not clarifying.

Macbooks are very expensive and because they're also particularly compact, they're susceptible to heat issues. Often the biggest point of failure for laptops with dedicated GPUs is the point where the chip is soldered to the motherboard. When the GPU produces excessive heat for prolonged periods (as when gaming or mining), this heat can actually degrade and eventually break the solder joints that attach the GPU to the motherboard. Sometimes this can be repaired through a process known as reflowing or reballing, but it of requires the full disassembly of the laptop, costs money and can never be 100% guaranteed to work.

At the current Litecoin difficulty (which will likely continue to rise), you'd be lucky to make $150 for an entire year of nonstop mining with your system and that's assuming that you don't pay for power costs. You surely wouldn't make enough to even pay for a replacement Macbook should mining destroy yours.

Nonetheless, I don't want to discourage you from mining entirely but definitely look into a dedicated rig if you can scrounge up the parts in the future.