Macbook pro heats up - trackpad and keyboard unresponsive

I have an early 2013 retina macbook pro 13inch with 8gb ram and the i7 processor running el capitan.

I started using smc fan control after this issue started and has helped a bit. But still an issue happening at times

Certain apps. Or even youtube or twitch.tv viewing can bring temperature up above 70 degrees Celsius

One the laptop reaches abot 71 or more the trackpad and key oard stop working.

Ionly the power button works but the video or program etc still runs. Doesnt crash or freeze only the keyboard and trackpad become useless.

After powering down and back up everything is fine.

Any ideas on what would cause this ? Or how expensive a fix it could be at a genius bar.

Thanks