You cannot boil brake fluid (in a brake system), but you can boil the water that the brake fluid absorbs over time, when this boils it creates steam which compresses easily so the pedal hits the floor, once the system cools down the steam turns back to water and the brakes work again.
Turn it off, or put it in Airplane mode.
Copy of user manual here http://www.samsunggalaxys4manual.com/ , have a look at call forwarding and set number to your voicemail number.