The relative efficiencies and decay times of alpha particle induced scintillations of CaWO4and CdWO4were investigated as a function of temperature in the range 10° to 375°K. Their behavior at intermediate and high temperatures is in agreement with that expected from the Mott‐Seitz‐Kro¨ger configurational coordinate model. Values ofEQ, thermal quenching energy, of 0.34 and 0.31 ev were found for CaWO4and CdWO4, respectively. As the temperature was decreased below 60°K, an increase in the decay times and a decrease in the relative efficiencies were found. This behavior can be explained qualitatively by assuming the existence of a trapping level.