This study proposes a novel 10-point numerical scale to evaluate long-term thermal comfort satisfaction. The available scale that verbally evaluates the short-term thermal comfort is thermal sensation vote (TSV) and this has substituted for the long-term thermal comfort assessment. However, the TSV has been questioned by many studies due to the ambiguous, widely different interpretation of each score and unequal perceived gaps between the scores. The paper argues the biological similarities between pain and temperature perceptions and proposes a numerical thermal comfort scale like that of long-term pain perception. Participants in a survey rated their long-term summer thermal comfort in the natural ventilation mode through the numerical and TSV scales. Ratings were compared after converting to degree hours based on monitoring temperature data for the same summer. The results show that the numerical scale provides an opportunity for respondents to express their long-term thermal comfort satisfaction level. Scoring by the numerical scale was convenient and clear to the respondents. The verbal scores of TSV, had different interpretations for individuals as each point was attributed to more than two values of degree hours. The score ‘Neutral’ was significantly ambiguous for assessing thermal comfort.