It is well known that an electric current increases the temperature of the material through which it is conducted due to the so-called Joule effect. This effect, which is used daily in domestic and industrial heaters, hair dryers, thermal fuses, etc., occurs because the new electrons injected into the material cannot go to the lower energy states because those are already occupied by the electrons of the material and therefore they must start their journey with relatively high energies. These electrons are called hot carriers. However, as they move through the material, hot carriers lose energy through collisions with other electrons and atoms in the solid. The process by which this lost energy is translated into thermal energy and, therefore, into an increase in temperature, is known as thermalisation of hot carriers.
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Source: Phys.org