I agree with the previous answer. To further the information, if a hardware issue is suspected, replacing/cleaning the heatsink fan is not a difficult task. To begin, remove the screw and pry a plastic cover on the bottom of the laptop. You have access to the fan once the plastic cover has been removed. The fan will be free after removing three screws, tape, and disconnecting a cable. At this point you can replace with a new fan or clean it by removing all visible dust. For further disassembly/replacement information, the W350I device troubleshooting page will be helpful.