Anthropogenic climate change is causing a global redistribution of the Earth’s biota, altering the geographic position of suitable climatic conditions for many species. Ectotherms, such as insects, have shown considerable variability in the direction and magnitude of their geographic responses to climate change. Of particular concern are the groups of insects, which provide services such as pollination, that are experiencing range contractions. To understand variation in extinction risk and species geographic responses to climate change, we must first understand the fundamental mechanisms that shape species distributions. In insects, such as diving beetles, it has been shown that species' physiological limits can be used to predict their geographic distributions; however, it has yet to be tested whether these relationships are consistent across life stages. Insects with complex life cycles are often characterized by ecologically distinct larval and adult life stages. For example, in odonates the larval stage is aquatic and lasts up to three years, while the aerial adult stage is terrestrial and lasts only a few days or weeks. Such striking habitat shifts result in life stage-related differences in the species' upper and lower thermal tolerances. The proposed study aims to assess how physiological differences between life stages might affect the suitability of physiology as a predictor of odonate distributions. To do this, we will relate measures of odonates' physiological thermal tolerances in their adult and larval stage to previously compiled data on the distribution of odonates in North America. The results will have important implications for predicting insects' geographic responses and vulnerability to climate change.