Understanding how organisms respond to variation in temperature and other environmental conditions is increasingly important in light of global climate change. Thermal plasticity across generations in addition to within-generation plasticity could have measurable impacts on survival and performance of organisms. However, few studies have adequately distinguished between effects due to trans-generational plasticity and selection (differential survival and/or reproduction) which could result in similar patterns. Here we use Manduca sexta to evaluate whether thermal conditions experienced by parents during development result in any significant effects (positive or negative) on survival, growth, development rate, and fecundity of offspring. To discriminate between effects due to trans-generational plasticity versus selection, we tracked families across two generations in order to directly compare parent performance and fitness to that of their offspring. Larvae in each generation experienced either control conditions or a 24h heat shock. Our initial results suggest that parental thermal conditions did affect offspring development; heat-shocked parent larvae produced offspring that developed faster than offspring of non-heat shocked parents. Further analysis will determine whether this pattern is consistent with trans-generational plasticity – indicated by offspring showing significantly faster development than their parents. Ultimately, this will improve our understanding of how temperature shapes performance and fitness in this system and contribute to the development of an improved framework for predicting the effects of extreme heat events on ectotherms.