This paper presents a comprehensive literature review on thermal adaptation in the built environment, focusing on the differences between air-conditioned and naturally ventilated buildings. The review highlights the limitations of traditional heat balance models, which assume a passive recipient of thermal stimuli and fail to account for complex factors such as past thermal history, cultural practices, and individual control. The adaptive model, in contrast, emphasizes the active role of occupants in shaping their thermal preferences through behavioral adjustments, physiological acclimatization, and psychological habituation or expectation. Key findings from field evidence include: 1. **Behavioral Adjustment**: Occupants make conscious and unconscious modifications to their clothing, activity patterns, and environmental controls to maintain comfort. 2. **Physiological Acclimatization**: While less studied, evidence suggests that physiological responses to thermal stress can change over time, particularly in high-temperature environments. 3. **Psychological Adaptation**: Perceived control over the thermal environment significantly influences thermal comfort and satisfaction, especially in naturally ventilated buildings where occupants have more control. The paper also discusses the limitations of climate chamber studies and the importance of field studies in understanding real-world thermal adaptation. It concludes by analyzing the impact of various factors, such as climate, economics, building design, and social customs, on thermal adaptation. The review provides insights into how occupants adapt to different thermal environments and offers implications for building design, control algorithms, and standards.This paper presents a comprehensive literature review on thermal adaptation in the built environment, focusing on the differences between air-conditioned and naturally ventilated buildings. The review highlights the limitations of traditional heat balance models, which assume a passive recipient of thermal stimuli and fail to account for complex factors such as past thermal history, cultural practices, and individual control. The adaptive model, in contrast, emphasizes the active role of occupants in shaping their thermal preferences through behavioral adjustments, physiological acclimatization, and psychological habituation or expectation. Key findings from field evidence include: 1. **Behavioral Adjustment**: Occupants make conscious and unconscious modifications to their clothing, activity patterns, and environmental controls to maintain comfort. 2. **Physiological Acclimatization**: While less studied, evidence suggests that physiological responses to thermal stress can change over time, particularly in high-temperature environments. 3. **Psychological Adaptation**: Perceived control over the thermal environment significantly influences thermal comfort and satisfaction, especially in naturally ventilated buildings where occupants have more control. The paper also discusses the limitations of climate chamber studies and the importance of field studies in understanding real-world thermal adaptation. It concludes by analyzing the impact of various factors, such as climate, economics, building design, and social customs, on thermal adaptation. The review provides insights into how occupants adapt to different thermal environments and offers implications for building design, control algorithms, and standards.