Those Y-series Lenovos are not designed well, thermally. If you want to keep it from throttling up and down due to heat accumulation (particularly on thr 4X00Xq CPUs) when gaming, go to your power options and make a gaming profile where the max CPU state is set to 99%. This will effectively disable the turbo on the CPU while using that profile and that will work wonders in regard to heat issues and CPU power usage. The baseline for the 4700mq, for instance is 2.4GHz, but when it jumps to 3.4GHz in turbo, it gets hot REALLY REALLY FAST in just about any laptop case.
At any rate, a consistant ~2.4GHz is better than throttling back and forth between 3.4GHz max and 800MHz!!!