All I can think about, for those who have the problem is:
-> A software you use got updated and is more system intensive (Chrome?)
-> Intel integrated graphics drivers got updated. Check out the driver control panel (newly added), and make sure that things are setup properly. These are my settings (a video I did which covers how to disable all color banding/dynamic contrast ratio, for best picture quality on the screen): GoodBytes Intel settings
-> Ensure that your fan are clean. Perhaps blowing a bit of air through the air holes will help.
-> Summer is coming if you are in the northern hemisphere, so temperature is warmer where you are, so the device gets warmer, especially if you don't have AC and it's hot already where you are. Although, I don't think it's a problem if you are in the state or Canada, I think we are all... enjoying... this extended winter.
Never heard the fans and haven't had problems with the display, maybe because I've used my SP2 hardly at all for graphics-intensive apps.
However, I have often seen CPU utilization going wild, at >30%, and the device getting warm. It does occur at random times, often without any indication in Task Manager or other utility that a particular application or service is going haywire. Sometimes it's just "System" or "System Interrupts" that is running at high %, but that's pretty non-specific. Better just to restart the SP2 when that's going on.
Can't see how the season has a whole lot to do with it. I bet few people use an SP2 outdoors, baking in the sun; indoor temperatures are pretty constant year round in most places. I think ambient conditions are rather unlikely to contribute much to overheating and high CPU loading that many users are reporting.