A strong external electric field in a plasma produces electrons with a temperature considerably higher than the temperature of the neutral gas in a plasma. We investigate here the currents produced by such electrons in a strong ac field. We discuss several cases of interest. Case 1 deals with the effect of a strong ac field on the plasma. It is found that the current has a component of frequency &ohgr; and a weaker component of frequency 3&ohgr;. The results are valid if &ngr;0>&ohgr;>&dgr;&ngr;0. Here &ngr;0is the collision frequency of the electrons and &dgr; is the fraction of energy transferred to the neutrals in a single collision. Case 2 deals with the effect of a strong steady electric field on which a weak ac field of frequency &ohgr; is superimposed. Here the current has a steady component plus an additional ac component of frequency &ohgr; which leads the ac field by a phase given by Eq. (33). Case 3 is similar to case 2 except that electron‐ion collisions have been considered. The measurement of the current and phases should lead to a determination of the collision frequency.