Understanding the energy consumption and emissions associated with health services is important for minimizing their environmental impact and guiding their adaptation to a low-carbon economy. In this post-hoc analysis, we characterize the energy burden of North American emergency medical services (EMS) agencies and estimate the potential marginal damage costs arising from their emissions as an example of how and why health services matter in environmental and energy policy, and how and why environmental and energy policy matter to health services. We demonstrate EMS systems are energy intensive, and that vehicle fuels represent 80% of their energy burden while electricity and natural gas represent 20%. We also demonstrate that emissions from EMS operations represent only a small fraction of estimated health sector emissions, but for EMS systems in the United States the associated marginal damage costs are likely between $2.7 million and $9.7 million annually. Significant changes in the supply or price of energy, including changes that arise from environmental and energy policy initiatives designed to constrain fossil fuel consumption, could potentially affect EMS agencies and other health services. We encourage cross disciplinary research to proactively facilitate the health system's adaptation to a low-carbon economy. (C) 2012 Elsevier Ltd. All rights reserved.