High idle temperatures / Fan speed issue with XFX Radeon RX 480

Hi there. I started using this card recently, and it didn't have any immediate issues. Upon starting up today, I noticed that the idle temperature on the desktop was around 45 degrees, normally it sits around 25-30.

Upon starting up a game (World of Warcraft), after a few minutes that temperature shot up to over 90 degrees and shut the computer down. I took a look at the fan settings on Wattman and it showed this:

http://imgur.com/a/6246B

Obviously, the fan isn't running quite that fast, however they are certainly spinning.

Please let me know if there's any more information you need.

Thank you very much for your assistance