The Brake Fluid we use in our cars, in of itself, needs to be a highly-resilient liquid considering the extreme temperatures in which it operates - add a couple of more tons of weight to an already heavy load, and an inadequate fluid could cost far more than a few new brake pads.
The incompressible nature of Brake Fluid transmits the single action of your foot against the brake pedal to the stopping of the motion of the tires. Residing in the brake lines, these fluids are exposed to incredibly high temperatures when they have to apply the pressure that squeezes brake rotors, forcing them to rotate slower. Should this fluid surpass its boiling point consistently, it is likely that brake failure is imminent, and one may need to make use of a runaway truck ramp or some other desperate measure.
Boiling brake fluid leads to the production of air bubbles within the brake lines. Air, unlike the fluid, is compressible: too much air in the system, and an unresponsive brake pedal you may have - amid a list of other obvious problems.
Keep your brakes - and yourself - protected. Choose a brake fluid from PSC that consistently performs.