web based games on Mac

Does anybody know if web-based games can make your computer run hard? I bought a macbook a couple of months ago and it has been running great so far. I started playing Evony, which is a web-based game which doesn't require any downloads and after a while of playing my fan starts to blow hard and I guess the computer is running too hot.

I was thinking that if the game is not saving anything onto my computer then it wouldn't overwork it. Am I wrong to assume this?

Is that a Flash game I'm assuming? Any time I run flash video through a website my computer starts to run hot also, but the fans kick in so I'm not too worried about it. Flash just really makes the CPU work hard I believe.

todd51 is correct. Streaming video, flash games, etc. will tax the CPU and GPU which in turn will cause heat buildup and the fans to increase RPM. All very normal. Buy a good notebook stand for your MacBook. A stand allows air to flow under and around the machine more easily and additionally provides some protection from nasty spills.

Regards.