 3 billion people worldwide rely on wood fuels for daily cooking, leading to negative health effects from smoke emissions. While global initiatives promote clean cooking stoves, their high cost and interrupted supply chains limit access in rural areas. Our research shows that biomass cooking stoves can significantly reduce smoke exposure for households in the developing world who cook outdoors. Therefore, policies promoting clean cooking should consider cooking location and ventilation to improve cost-effectiveness. This article was authored by George Langbein, George Peters and Colin Vance.