Games : Is my gpu temperatures high? How can i lower it?

I've recently bought a Gigabyte R9 280x 3gb gddr5 graphics card, and honestly, i'm pretty happy with it. But one thing i'm concerned is with it's temperature.

After one hour or so playing, its temperature goes to 70-72C.

I've only tested it with two games

Resident Evil HD remaster
Skyrim (with mods)

Both with max filters @ 1080p.

I guess that skyrim is a heavier game than RE, or am i wrong? And i've got the same temperature. Is it too high? What is its risk temperature?

How can i lower its temperature without underclocking or undervolting?