Cpu overheat?

I'm using the Predator Helios 300. It seems to be able to run games like Rust and GtaV on fantastic settings but after playing for a while, there are some frame drops that last for only couple seconds that occur between about some amount of minutes. I don't know much about computer hardware but that sounds like some heating issue, since when I go to the control panel, the cpu seems to go above 90 sometimes. It probably begins to bottleneck after that point which I assume is the cause of these. These happen on all cpu clocking speeds, but I don't see difference in the interval really.

I did also try to rise the back of the laptop off the table just a bit, I think it helps with the temperature a tiny bit and also think it reduced those lags, had only like 2 from maybe 2-3hr session.

If you can point out exactly what is the cause and what to do about it, that would be really helpful. Thanks in advance.