Introduction to Outdoor Thermal Comfort Research

This chapter provides an overview of research progress in outdoor thermal comfort, focusing on the challenges associated with dynamic and complex outdoor environments. The growing importance of outdoor thermal comfort is first introduced in the context of urbanization, climate change, and increasing outdoor activities. The evolution of thermal comfort research from indoor-oriented frameworks to outdoor-specific indices and field-based approaches is then reviewed, highlighting advances in environmental measurement, human physiological responses, and psychological and behavioral adaptation. Key methodological developments in assessing wind, radiation, and surface temperatures are summarized. Major unresolved issues are subsequently identified, including measurement uncertainties, human variability, limitations of existing thermal comfort models, and heat-related safety concerns. Based on these challenges, the chapter outlines the structure of the book, covering environmental measurements, human-centered factors, model evaluation and improvement, safety-oriented applications, and design strategies for outdoor thermal mitigation. This chapter establishes a conceptual foundation for the subsequent chapters and frames future research directions in outdoor thermal comfort.