The responses to gamma-irradiation of 70 nm and 140 nm gate oxide thickness MOS dosimeters are characterized at different temperatures during oxide charge buildup and radiation induced charge neutralization. Three contributions to the threshold voltage evolution are observed at different ranges of temperatures and gate voltages: a shift in VT caused by a change in the built in potential, thermal annealing which occurs even during irradiation, and a third contribution probably associated with changes of transport or capture parameters with temperature.