Relating to temperature rise, the flow of heat, or cooling of components
Excepting superconductors, current flow through any conductor results in energy being converted to heat within that conductor. This results in a temperature rise within the conductor. As all materials have a maximum safe operating temperature, failure to properly dissipate this heat can result in failure of components.
Heat flows from hot objects to cooler ones, by the laws of thermodynamics. As such, it is possible to assist heat dissipation by providing a low-impedance thermal connection between the component generating heat and some other material known as a heat sink. Eventually, the heat sink (or sinks) must dissipate their heat to some other surrounding substance, typically the atmosphere of the Earth.