Wild bee decline has been linked to multiple stressors driven by climate change, including increasing temperatures and emerging infectious diseases. Species’ thermal tolerance is thus an important physiological trait to understand, as it defines species’ realized niches and evolutionary capacity to respond to climatic changes. Temperature conditions at both broad and fine scales can modulate thermal tolerance in wild bees but little is known about how climatic patterns at different spatial scales impact these traits. Thermal tolerance can also be modulated by behaviors (e.g., looking for a shaded area if there is a risk of overheating under direct sunlight). We are currently investigating thermal tolerance in male and female squash bee (Eucera pruinosa) populations across sites that naturally vary in temperature at both broad and fine scales. Our goal is to develop a predictive model of risk of thermal stress for this important crop pollinator.