This has happened to me several times.
This only happens if you do not let your computer/laptop cool down for 30 minutes. It overheats and it shows this message before it shuts itself down.
So make sure you...
~ Shutdown your laptop/computer every hour for 30 minutes to let it cool down
~ Do not put your hands on the sides of your laptop where the fans are.
They are a couple tips to stop this happening. I am not an expert in computing, but this is just something that everyone should need to know.