i have seen this before, i was playing painkiller on my firends computer a few weeks ago and the ground turned to checkerboard pattern with lots of lag. we looking into it and found out that it is a video card problem...
I don't believe it's an overheated card problem in this case. I've had a similar issue. It only started last night when I got about 1/2 way through the Riverside Province mission. In my case, the ground went white and things became jerky right after I got the staff. Finishing the mission cleared things up for the cutscene and then it happened again while I wandered the safe zone in Sanctum Cay. If it was a heat issue, I'm certain my problem would have manifested itself long before now.
I don't know what the problem is, I logged the issue and updated my drivers. I dont believe its a heat issue, I play plenty of other games and have never had this problem before. If I run into a town or back out into the world it fixes itself.