con·vec·tion ( P ) Pronunciation Key (kn-vkshn)
n.
Physics.
Heat transfer in a gas or liquid by the circulation of currents from one region to another.
Fluid motion caused by an external force such as gravity.

Convection doesn't help cool solids as well as it helps to heat the surrounding air, and heat surrounding solids with that heated air.

heat sink
n.
An environment capable of absorbing heat from an object with which it is in thermal contact without a phase change or an appreciable change in temperature.
A protective device that absorbs and dissipates the excess heat generated by a system.

The only other way I can put it is that good brake pads act as a thermal barrier to help prevent heat transfer to the calipers and fluid by having a very aggressive heat gradient from the surface of the pads to the backing plate.

Of course, there really is no viable way to cool the calipers on most cars, so it's largely ignored. Only system I've seen for such an end has been on Semi-truck racers in Britan, where they have a forced water spray on the calipers and rotors.

The main reason I mention this at all is because heat is what allows brake fluid to absorb water faster than nature would, and water is what kills brake fluid effectiveness.

Anyways, I think I've gone on enough of a tangent, since I just had to re-read the initial post to see what the topic was h: