DIAGNOSIS This is typically the overload protection kicking in. The saw's motor has a thermal cutoff to prevent damage if it's working too hard, which can be triggered by a dull chain or pushing too hard.
FIX First, let the saw cool down for 5-10 minutes. The main fix is to sharpen your chain. A dull chain forces the motor to work exponentially harder. Use a round file that matches your chain's pitch (likely 3/8" low-profile) and follow the existing angles on each cutter. Make sure you're filing every cutter to the same length. After sharpening, try making a cut without forcing the saw—let the sharp teeth do the work.
IF THAT DIDN'T WORK Check that the bar and chain are properly lubricated. A dry chain creates immense friction. Fill the oil reservoir with bar and chain oil, start the saw (pointing the bar at a piece of scrap wood or the ground), and rev it to see if oil is flinging off the tip of the chain. If not, the oiler port might be clogged.
HEADS UP Don't ignore this shutdown. If you keep triggering the overload repeatedly, you can permanently weaken the motor. Sharp chain, proper lubrication, and letting the tool cut at its own pace are the keys to keeping this saw running cool and long.