The results of a number of screening experiments are reported that were designed to seek hydrogen donor molecules that function as high-temperature stabilizers (i.e., >400 degrees C) in jet fuels and similar hydrocarbon mixtures. The most important conclusion of this work was that in the temperature range between 400 and 450 degrees C, 1,2,3,4-tetrahydroquinoline (THQ) was by far the best thermal stabilizer that we have discovered to date and significantly more effective than benzyl alcohol (BzOH), our previous benchmark.