No i can't tell you why you've got that difference.Probably stress on the card,why one game stresses the card more i don't know.
Can you do the next so i can see what components get that hot,
Download the next program,
http://www.hwinfo.com/download32.html
You can open hwinfo32,after that open the sensor window by marking sensors=V,after that click run,,then click at the bottom "Logging start" ,after that choose a name and place for the log.like Hwinfolog at your desktop.Leave it open and do game/stresstest (15min->30min.).The log will end at that point but will be saved.
After the restart upload the log to a site without to much crap (!),for instance dropbox,and leave a link to it here.