Heat acclimatization is a physiological adaptive response in the human body exposed to high temperature environments over a long-term. It involves the regulation of the central nervous system, cardiovascular system, and other systems. Research on heat acclimatization mechanisms covers multiple aspects, including systemic, cellular, and molecular levels. The activity and electrophysiological changes of warm sensitive neurons are closely related to the formation of heat acclimatization. Heat acclimatization exhibits environmental and temporal effects and is closely related to training modalities. Different training methods are suitable for different populations, and evaluation of heat acclimatization requires integration of physiological, biochemical, and metabolic markers. This article reviews the research progress on physiological changes and mechanisms, biomarkers, and training methods of heat acclimatization, and prospects future trends in theoretical research and training practice of heat acclimatization.