Surprise! Surprise! Can you help yet again with a computer problem?

For the past two days my laptop has been getting extremely hot. If it sits on my leg it will burn me literally. I haven’t been using it anymore than usual. Yesterday it started shutting down without warning. Is there anything I can do to avoid it overheating? If you have any tips I would greatly appreciate it! Thanks (:

I almost forgot my icons in the bottom right corner on my bar keep disappearing! What could be causing this?