Your brakes operate on a hydraulic system, which means they use fluid to transfer the power of your foot into force on your wheels. The master cylinder starts this chain reaction. Heat generated by heavy or prolonged breaking may affect brake fluid.
Keeping your brake fluid topped up and checking it for cleanliness will ensure smooth communication from your foot to the master cylinder.
Regular servicing will check the boiling point of your brake fluid, its recommended that you change your brake fluid a maximum of every 2 years if not beforehand.