Most computers today are designed to turn off automatically if any of its inner components overheat. Often, heat related issues occur when the computer is working hard, e.g. playing a graphically intense computer game. There are number things that can be check quickly, for example, power supply fan to see if its running, listen for the CPU fan, if there are case fans attach connected to the motherboard they need to be check. If still need help submit a help desk ticket.