Ok, here's the issue. No matter what kind of games you try to run on an integrated Intel GPU (what you have) it is going to get hot. Really HOT. The thing is, your CPU and integrated GPU are going to work at maximum capacity to provide the best experience. The Intel GPU (which ever it is, doesn't really matter since they all pale in comparison to dedicated GPUs) is going to start first at maximum capacity. Once it recognizes that it needs more processing power it will call on spare cpu cycles to make up for what it lacks. Luckily for you, the i5 in your machine has hyper-threading (two physical cores and two imaginary cores). Of course, said program needs to support hyper-threading in order for this to work properly. In the end, your CPU and Intel GPU are going to work like hell to push out as many frames as possible. That results in a shit ton of heat.
Now for the good news! Should your laptop get too hot, it will most likely blue screen before it causes any permanent physical damage (I'm not quite sure why it doesn't just say "Hey a-hole, go get a life while I cool down for a while!!", oh well). Should this happen, let your laptop cool down for at least an hour, go out, get a bite to eat, read the paper and you should be good to go.
Make sure the vent(s) are clear of any dust or debris, keep your laptop elevated and the vent(s) facing an open area (not up against a wall, for instance).
tl;dr
This website explains everything rather well.
http://www.laptop-overheating.com/Good Luck