Thank you for your inquiry. Heat issues with the 8xxx and 9xxx series of Nvidia Geforce cards are somewhat common because these video cards were usually 'factory overclocked'. This resulted in better performance for the cards, but also increased stress on them. Eventually age and dust or other airflow restrictions can make it more difficult for your card to disperse heat. When this happens, if your video card overheats, it can cause permanent damage to the video card making it less able to disperse heat or rendering it unusable. New updates sometimes bring new graphical features which put further stress on your video card, but more often new updates bring higher numbers of players to the game servers. When this happens, your video card has to display more character models and textures in public areas which places further stress on the video card and can result in overheating if your videocard is not dispersing heat well or correctly.
While we are sorry to hear about your situation, this could have happened with any game that was demanding on your video card. We would recommend periodically cleaning out your system case and fans to make sure your system has good airflow, and periodically checking the temperature (via your video card utility typically) of your video card to avoid this problem in the future. Additionally, we would not recommend overclocking your video card. If you purchase any video cards in the future, you may want to check whether these are 'factory overclocked' as well. If so, we would recommend reducing the clock speed to the speed recommended by your manufacturer to reduce stress on the card and lower the risk of overheating.