high temperature problems with macbook pro 13"

is it normal behaviour ?

Yes. Videos are processor-intensive actions, and gaming is even more so.

There is nothing you need to do, other than provide adequate air circulation so that the MBP can dissipate heat properly. The aluminum case is specifically designed to do that, so it's normal for it to feel quite warm. Don't use cases or "skins" because they will impede heat dissipation, and don't be tempted to install some clever hack to make its exhaust fan run faster. That will just draw more needless dust inside.

If the MBP gets too hot it will reduce its processor load automatically, and if that fails to reduce its temperature it will simply shut down on its own.

You should consider upgrading to Yosemite. It's completely subjective but all my portable Macs seem to run cooler with Yosemite than they did with Mavericks. Their battery life is much greater though. That's not subjective, I measured it. If the battery life is greater they are almost certainly running cooler.

Back up your Mac prior to upgrading OS X, as a precaution against the unexpected. To learn how to use Time Machine read Mac Basics: Time Machine backs up your Mac - Apple Support.

It is also possible you have 3rd party additions that are contributing to your CPU and Disk usage while you are playing games or watching video that are accelerating the speed at which your battery drains. For example anti-malware products, Mac cleaner products, memory cleaner products. All are unneed on a Mac and generally contribute to performance issues, kernel panics, and in the case of laptops, speed the battery drain. EtreCheck can help identify 3rd party additions.