JouleEffect

The thermal effect of the electric current is represented by the dissipation of heat in a conductor crossed by an electric current.This is due to the interaction of current particles (usually electrons) with the atoms of the conductor, interactions by which the former yield to the latter of their kinetic energy, contributing to the increase of thermal agitation in the mass of the conductor.
The Joule effect, or the electrocaloric effect, shows that when heat passes through a conductor, heat is emitted in proportion to the resistance of the conductor.

The Joule effect is manifested as long as the conductive environment has a certain electrical resistance, because, below a certain value of temperature, very low, the resistivity of the conductors decreases suddenly to low values, resulting in the phenomenon of superconductivity.

Mathematically, Joule's law is expressed as follows:

H = I 2 ∙ R ∙ t
or you'll find Joule's law written like this:
E = I 2 ∙ R ∙ Δt