The present research emphasizes the role of learning in response changes to infection threats and suggests a new instrument. This preliminary study aims to develop a brief tool (SITS: Sensitivity to Infection Threats Scale) that measures individuals' health sensitivity to infection threats. The present research utilized the Brief Symptom Inventory-phobic anxiety and hostility subscales and the newly developed SITS. The reliability and validity of SITS were examined through construct, divergent, and convergent validity as well as internal consistency and test-retest reliability. The underlying dimensions were explored through an exploratory factor analysis (EFA N = 142; Mage = 20.29, SDage = 2.34), and the EFA dimensions were confirmed through a confirmatory factor analysis (CFA N = 236; Mage = 20.36, SDage = 2.24). The EFA and CFA results supported a correlated four-factor model and the 20-item structure of the SITS. These four factors included Preoccupied, Avoidant, Physiological, and Cautionary Sensitivities. The overall scale and subscales had good internal consistency, test-retest reliability, and convergent and divergent validity. The SITS is a reliable scale and has the potential to deepen our understanding of human behaviour in responding to infection threats.