F̶̲̥̅̊o̲̣̥я̲̣̥ a metallic conductor,Ohm's law holds provided

not sure just what you're after, but current in a conductor can cause it to heat, changing the resistance.

Ohm's Law says I = E/R, and assumes a constant value for R. Heating may alter this, though at any instant the relation still holds, if the changing R is taken into account.