What makes you say, "overheating"?
Did the unit shutdown abruptly? If not, then no overheat occurred.
90 degrees Celsius is not abnormal for the situation you describe. On a daily basis, I see similar temps. As long as the fan is running at a high speed, there isn't much you can do, other than stop gaming.
If the temp exceeds 100 degrees, then you have overheating.