INTRODUCTION: Thermal sensation and thermal comfort scales are widely used in human physiology research to quantify human thermal perception during different thermal interventions or in response to varying behavioural modifications. Much of the categorical terminology of Gagge and colleagues’ seminal early work from the 1960s persist (e.g., sensation: cold, cool, neutral, warm, hot; comfort: comfortable, slightly uncomfortable, uncomfortable), and today, are evaluated using different Likert and/or visual analogue scales. However, a consistent feature of all thermal perception testing to-date, is that perceptual data is collected at discrete timepoints (e.g., 1, 3, 5, 10, or 30 minute intervals). Consequently, discrete timepoints offer poor temporal resolution, particularly when perceptual shifts in sensation and comfort are transient and unpredictable. Therefore, our objective was two-fold: 1) to develop an efficacious tool to continuously measure thermal perception; and 2), to explore the continuous thermal perceptual patterns during fluctuating and transient ambient temperatures at rest. METHODS: Fourteen healthy participants (7 female and 7 male; 30±4 years, 1.9±0.2 kg/m²; matched for age, body mass index, and hours of moderate physical activity/week) visited the laboratory on two separate days within the same week, and underwent 30 minutes of transient fluctuations in ambient temperature (ranging from 15 to 35 °C) in a repeated measures blinded design. Participants were asked to continuously monitor their thermal sensation and comfort, and utilize the newly developed perceptual slider tool, to reflect their sensation and comfort. Following ethical consent, background questionnaire and familiarization with the perceptual slider tool, participants were instrumented with skin temperature thermistors and skin heat flux sensors on the hand, lower back and calf, to calculate mean skin temperature and mean skin heat flux. Accuracy (in the context of ambient temperature) was assessed using repeated measures correlations (R_rm) and repeatability (across both thermal profile tests) was assessed using linear regression analysis. Mixed effect modeling was used to explore the variance of predictors on thermal sensation and comfort. RESULTS: Across a fluctuating temperature profile, the perceptual slider tool demonstrated 1) high between-day repeatability and accuracy of thermal sensation (R²=0.85, P<0.001; R_rm=0.85, P<0.001, respectively); and 2) moderate repeatability and accuracy of thermal comfort (R²=0.70, P<0.001; R_rm=0.56, P<0.001, respectively). Both mean skin heat flux (R_rm=-0.61, P<0.001; R_rm=0.37, P<0.001) and mean skin temperature (R_rm=0.43, P<0.001; R_rm=0.11, P=0.004) were significantly associated with thermal sensation and comfort responses, respectively. Sex, age, body surface area-mass ratio and hours of moderate physical activity/week were not significant predictors of either thermal sensation or thermal comfort. CONCLUSION: When perceptual shifts in sensation and comfort occur, due to variations in ambient temperature, the continuous perceptual tool demonstrates high accuracy and between-day repeatability. At rest, the hierarchical associations with thermal perception (i.e. in order of from most significant) are ranked as ambient temperature, mean skin heat flux and mean skin temperature. By continuously measuring perceptual metrics, we will be able to better understand the interplay between psychophysical and physiological relationships of sensation and comfort – with an overarching purpose to help design more efficient and efficacious thermal strategies for the future.