Coolant

A coolant is a fluid which flows through or around a device to prevent the device from overheating, transferring the heat produced by the device to other devices that either use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert, and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.