Bitcoin-Qt is shutting down my laptop
You can limit CPU (even per core) usage per process. Doing so would keep your CPU cycles low and wouldn't cause all that trouble to your computer. 

The best way to do this is to set soft limits directly to your O/S, as described here.

A freeware that also works is: cpulimit, although I would strongly suggest you tune you real-time process management directly from your console, as described above.