The lower flammability limits of 18 C(x)H(y)O(z)N(w) liquids were measured as a function of initial temperature in an ASHRAE 12 L style apparatus. Results indicate that the calculated adiabatic flame temperature is not constant, as previously reported but rather decreases with increasing temperature. Consequently, the modified Burgess-Wheeler law does not accurately predict the effect of temperature on the lower flammability limit. Though few direct comparisons are possible, previously reported data agree well with the values measured in this study.