Thermally ionized gases which are subjected to electrical fields show non-equilibrium effects which can be detected both spectroscopically and electrically through changes in the electron energy distribution and number density. Some experimental results are presented for argon at several atmospheres pressure and low seeding ratios (<10^-5). At the relatively low electron densities used (similar 10¹⁰ cm^-3), transitions from diffuse conduction to arc-type discharges occur before any significant increase in conductivity is obtained due to electron temperature enhancement.