Most molds are killed off by temperatures of 60-70°C (140-160°F). Thus, boiling water is generally enough to kill off mold. Remember, though, that mold doesn’t just grow on the surface: heat will have to penetrate into whatever the mold is growing in to kill it. Also keep in mind that the mycotoxins produced by certain mold can survive intense heat: boiling may kill the mold but leave its poisons still intact.