Objective: Based on the theoretical framework of Risk Perception-Efficacy Appraisal-Behavioral Response, the study aims to explore the group heterogeneity in high temperature health risk perception and behavioral responses among college students in Chongqing, so as to provide a scientific basis for implementing differentiated health interventions. Methods: A multi stage cluster sampling method was used to select 856 students from five universities in Chongqing. Data were collected using a validated questionnaire. One way analysis of variance and independent samples t-test were used to analyze individual differences, Pearson correlation analysis was employed to examine relationships between variables, multiple linear regression was used to identify influencing factors, a structural equation model was constructed to validate the theoretical pathways, and the Bootstrap method was applied to test mediating effects. Results: In the risk perception dimension, the severity score of high temperature health hazards among college students (3.28±0.89) was higher than that of susceptibility score (2.94±0.93). Efficacy appraisal showed that the response efficacy score was the highest (3.91±0.81). In behavioral responses, adaptive behaviors were most prominent (5.43±2.75), while emergency preparedness behaviors were the lowest (2.71±1.33). The structural equation model validated the pathway of "threat appraisal → efficacy appraisal → behavioral response" ( χ 2/df=2.49, RMSEA =0.05). Self efficacy played a fully mediating role between threat appraisal and behavioral response, with a mediation effect value of 0.10 (95% CI =0.02-0.19). K means cluster analysis categorized the subjects into three groups, with the core barriers to behavior being economic constraints (22.3%), lack of motivation (34.8%), and insufficient cognition (34.1%), respectively. Conclusions Decision making regarding high temperature health behaviors among college students follows psychological pathway of "cognition-appraisal-action" with self efficacy serving as a key mediating variable driving behavioral change. Targeted interventions should be implemented for groups with different characteristics.