Well laptops usually run hotter than desktops, so I'm assuming the heat has slowed your CPU down. Have you tried lifting the laptop off the tabletop (put something under on the sides) to allow more air to flow underneath as cooling?
yes the M3 is a crazy hot laptop, and it was an issue.
I followed a guide to under volt it.. and used a program called Right Mark CPU clock utility - works awsome!
I guess the Toshiba APCI drivers - power controls had been messed up whatever.. but this took it over.. runs it great.. does not interfere, and I can adjust voltage to the cpu.. and have managed to lower it quite a bit so that it does not run near as hot. At full load I have reduced the temp over 15*