First of all you are dealing with a heat issue here, usually most modern motherboards (the base where the little parts are connected to make your computer work) are equipped with a heat sensor, if the heat is too much, it shuts down by itself so that it does not damage the main processor (CPU) in this case take it to a repair guy and ask him to have your cpu fan changed, if its an IBM then you can take it to the dealers of IBM so that they can replace it with the one that is designed for the structure of ure laptop. Hope this helps. Cheers!