The Routledge International Handbook of Heritage and Affect brings together leading and emerging scholars, practitioners, designers, and artists to examine how heritage environments shape and are shaped by affect, emotion, embodiment, and power. Addressing museums, memorials, landscapes, and immersive heritage practices worldwide, the volume situates affect at the center of contemporary heritage theory, methods, and practice. Organized in six thematic sections, this handbook bridges foundational debates with applied questions of heritage design, immersive media, architecture, and professional ethics. Across global case studies, the chapters show how places of heritage operate as designed atmospheres that move publics, configuring perception, memory, and political subjectivity, while also revealing how affective encounters can cultivate empathy, reproduce exclusion, or mobilize collective action. This volume integrates more-than-representational and contextual approaches to trace the motion of emotion across museums, memorials, archives, and landscapes. It also advances methodological innovation, from multisensory and multimodal ethnography to computational analysis and wearable biosensing, offering readers concrete tools for research and practice. Throughout, contributors foreground care, consent, accessibility, and justice, especially in sites of difficult heritage and cultural trauma, equipping readers to critically design, interpret, and steward heritage environments in a technologically accelerated and politically polarized world. This handbook is for scholars and postgraduate students in heritage, museum and memory studies, cultural geography, anthropology, architecture, and digital and immersive humanities. It will also be valuable to curators, heritage professionals, exhibition designers, planners, artists, and educators seeking ethically grounded ways to understand, curate, and evaluate affective experience in museums, memorials, historic sites, and heritage landscapes.