With the development of antibiotics, infectious diseases once subsided, and when I was attending medical school, laboratories related to infectious diseases changed names one after another and disappeared. However, it can be said that the era of infectious diseases has begun with the emergence of resistant bacteria and the emergence of new infectious diseases accompanying internationalization. There are simple antibody tests for influenza, genetic tests (PCR) for coronavirus, etc., and diagnostic imaging using CT. However, the dominant tool for suspicion of infection is still body temperature measurement. Vitarate is intended to evaluate the heat load during work and exercise, but may have new possibilities in the diagnosis of fever in the future. Continuous measurements, measurements that do not require contact with healthcare professionals, and the ease of recording can be tools for the future.