An investigation on humans' sensitivity to environmental temperature

While earlier investigations into thermal perception focused on measuring the detection of temperature changes across distinct bodily regions, the complex nature of thermal perception throughout the entire body remains a subject of ongoing exploration. To address this, we performed an experiment using four climate chambers with oscillating temperatures between 24 °C ± 1 °C. Our study involved 26 participants who moved between these chambers and had the task of reporting whether the second chamber entered was warmer or colder than the previous one. We collected 3120 temperature judgments, which we analysed via generalised linear mixed-effects models. The results showed surprisingly accurate temperature discrimination abilities and limited variation between individuals. Specifically, the Point of Subjective Equality stood at - 0.13 °C (± 0.02 °C), the Just Noticeable Difference (JND) was 0.38 °C (± 0.02 °C), the JND95 (indicating 95% accuracy) 0.92 °C (± 0.05 °C), the negative ceiling performance level (CPL) was - 0.91 °C (± 0.28 °C) and the positive CPL 0.80 °C (± 0.34 °C). The implications of the JND95 and the CPLs are particularly noteworthy, as they hold potential to significantly contribute to the advancement of intelligent algorithms for temperature control systems within building environments.