This paper suggests that the thermal state of a processor can be approximated using data flow analysis. The results of this analysis can be used to evaluate the efficacy of thermal-aware compilation strategies, or as input to thermal-aware optimizations that occur in the early stages of back-end compilation. We propose different ways how the exploitation of thermal behavior knowledge can be included in the different compilation phases. Categories and Subject Descriptors C.1 [Computer Systems Organization]: Processor Architectures General Terms Algorithms, Theory Keywords Thermal Management, Compiler.