More than likely, you don't even have the warranty through Toshiba, since those are only one year unless you bought and extended warranty through them. I'd first look and see if there is any dust around the intake ducts and blow it out with a can of air. Another thing I'd check is to see if the Intel chip even throttles down. I know AMD chips with PowerNow it can throttle the processor speed. I'd also check and see if there are any processes that are using an abnormal amount of memory and also what the CPU load is.