In most cases where a laptop gets warm to the point it turns off is because the cooling system is not working as it should. Computers and laptops are programmed to switch off automatically when reaching a certain temperature to avoid damage to the different components inside the computer. You can check these values by accessing the BIOS during computer start-up.
Generally this problem happens because the cooling vents are obstructed which prevents the hot air to go out.
The best way to resolve this matter is to clear the vents, not only on the outside but on the inside. So for this you have to be handy and be used to assembly/dis-assembly tasks.IMPORTANT: It is strongly NOT recommended to disassemble your computer if you are not used to this. It is better in this case to have a technician do it.
So, if you are sure you can do it by yourself, then follow the below steps.1. Disassemble the computer.
Disassembling the computer can be a complex task if you are not used to it. First of all, you you will need to locate the fan. Once found, remove the fan and clean the vents. You will be surprised by the amount of dust that can be found in there.
Bottom view : Location of fan2. Cleaning
Once the fan is located and removed, you can now remove the dust obstructing the fan. Using a hand aspirator can be of a great help here.
In this picture, I have located the electrical connector and also the most important area you have to clean. This is where dust accumulates and blocks ventilation. When clean, you should be able to see through the other side.
Also make sure that the other vents are not obstructed .3. Replace the fan
Now you can reseat the fan in its place. Make sure not to forget to plug the connector or else the fan will not work as it will have no power supply.4. Assemble the computer.
Now you can assemble the computer and the problem should now be resolved.
(http://tim.id.au/laptops/acer/aspire%206530.pdf) is a link to the service manual of the Acer Aspire 6530. It will explain how to dis-assemble and re-assemble the computer. Please make sure to read it carefully and understand it before attempting anything. Again, I would strongly recommend you to go to professional if you don't feel doing it.
Glad to help you.