Temperature and moisture affect organisms through their operational environment and the thin boundary layer immediately above their tissues, and these effects are measured at short time scales. When a human (a mammal) wearing a dark insulative layer walks outdoors on a cold but sunny day, he or she feels warm because energy from the sun is interacting with the dark clothing, creating a warm boundary layer to which his or her body reacts. Conditions beyond that thin boundary layer are physiologically irrelevant. Walk into the shade, and suddenly one is cold because the warm boundary layer has been replaced with one at the ambient temperature of the air. This example demonstrates many factors to consider when evaluating the degree to which a change in climate will affect an organism. Climate is defined as the long-term average of temperature, precipitation, and wind velocity. “Long term,” when applied to climate, is a relative term and can refer to periods of weeks to centuries. In the context of climate models, results are generally reported as averages across 30-year intervals, which for many animal species represent multiple generations. Our ability to infer the biological effects of projected long-term changes in temperature and precipitation relies both on our ability to directly relate these multiyear averages to biological responses, and the trophic distance between climate-induced ecological change and its effects on specific biological relationships.