You are right and wrong. Applying thermal paste can cause an increase in temps, but it has nothing to do with mining. It has to do with how much you're using. Your tube should tell you how much to apply, but if it doesn't just try to keep it spread fairly thin. Don't spread it like you would a peanut butter sandwich or you will most likely have issues with temp.
ahh yes forgot to mention that, was assuming he would know how to apply it (watch a vid), but for the most part it should help temps