Perhaps it's a mix of strangely hot British weather and poor ventilation in my computer, but even during summer of last year I was having no problems with my computer overheating. However, in this weather my computer can't game for half an hour without the CPU reaching over 70C, and the other day I even saw it at nearly 100C (I'm measuring the temperature with SpeedFan). Perhaps it's never really been hot enough for me to notice before, but if my CPU can't go for two hours on a game without overheating and turning off (in only about 25C weather), I seriously need to be looking at more cooling solutions - or at least I think so, unless you can suggest something else might be going wrong. Adding more fans seems to be ineffectual with the poor casing I have (the CPU fan blows straight into a closed-off panel, musta been the shitty custom building company I used), getting more casing will be costly and I have no idea how I'll be able to get casing with the relevant holes to where my CPU fan is, and water cooling and these other hi-tech solutions seem like overkill for my system. Oh, and my CPU is an AMD Athlon 64 X2 5200+ 2.7GHz (so not exactly a powerhouse either), and has an extra fan I paid for stuck over the heatsink. Dunno whether that information will help. I'm guessing re-sorting out the casing and fan position would be my first priority, but I have no idea what the best way of doing it would be.