Phillip Corcoran said:
A PC or laptop typically shuts down suddenly when the internals reach a critical temperature, and the shut down occurs to prevent damage to vital components. So I would start by investigating the reasons why it might be overheating:
1. Don't use the laptop directly on your lap or any soft surface. It must be on a hard, flat surface where air can circulate under it.
2. Check the cooling vents on the side and underneath, they may have a lot of dust in them so clean them out.