The use of body temperature measurements has played an essential role in disease prevention and identification in recent years, especially during the COVID-19 pandemic when a high body temperature identified infected patients. In this study (Study ID: STUDY0000269), we focused on the correlation between new, daily, local cases of COVID-19 and patients with high body temperature (above 99 F) upon entering a non-urgent medical practice. A reliable screening method is expected to detect more patients with COVID-19 symptoms as COVID-19 cases become more prevalent, supporting that it is a reliable method. A secondary aim of this study was to analyze the relationship between environmental temperatures and changes in the frequency of patients with high body temperature. This study examined a subsample of over 3,000 patients in a medical practice. Results showed a negative correlation between high body temperatures and daily positive cases of COVID-19. The study also demonstrated that environmental temperature predicted patient body temperature.