There's nothing in your screen shots that indicates high demands on system resources. If you're visiting sites with Flash content, that could be a culprit. Generally speaking, Flash is notorious for consuming system resources, raising temps and decreasing battery life. For Flash-related issues:
- Find your Flash version and make sure it's the latest version available. Never install or update Flash from a pop-up on a website. Always go to Adobe's site to get Flash or updates.
- Install ClickToFlash (Safari), Flashblock (Firefox) or FlashBlock (Chrome) to control which Flash content plays on websites.
- Try using the YouTube HTML5 Video Player to watch YouTube videos, when available. (May impact fullscreen viewing. See link for details.) Some have reported better performance with HTML5, while some have reported worse. Try it and find out what works best for you.
It shouldn't have anything to do with the display. I've seen some threads on wake from sleep issues, but I don't recall the details. You might try searching the forums for "wake from sleep" and read a few of those threads, to see if any applies to your situation.