Objective: A computer simulation model was constructed to analyze the effects of anesthesia-induced thermoregulatory system impairment and low-temperature environment of the operating room on the perioperative thermoregulation of individualized patients. Method This study proposes a simple anesthesia model and incorporates it into our developed individualized thermoregulatory model，which can be used to assess the effects of individualized characteristics such as age, obesity, and cardiovascular disease on thermoregulation by modifying different model parameters. Modeling the effects of general anesthesia on human thermoregulation can be achieved by reducing basal metabolic rate and the thresholds for vasoconstriction and shivering. Results: The model simulation results show that the elderly show lower core temperature but higher skin temperature, compared with the young people. In a low-temperature environment, an increase in fat thickness or an increase in the severity degree of the left ventricular failure may alleviate the decrease of core temperature, while an increase in wind speed or relative humidity can result in a decrease of core temperature. Most strikingly, when the threshold setting of vasoconstriction is reduced by about 0.5-3 ° C, the core temperature decreases down to as low as 33° C. Conclusions: By comparing model simulations with experimental measurements, the reliability and validity of the model in predicting human transient thermal responses during varying external thermal environment was verified. With this model, we found the individualized characteristics of the human body have an important influence on human body temperature in a low-temperature environment. Moreover, the combination of individualized characteristics of the human body and general anesthesia further complicates the body's thermoregulation and poses significant challenges for clinicians.