## 3 Experiments and Analysis of Results
### Experiment Conditions and Procedure
#### 3.1.1 Data Analysis  
During the experiment, we set a series of different indoor air conditioning temperatures ranging from 16 \({}^{\circ}\)C to 30 \({}^{\circ}\)C to simulate different temperature conditions. Due to the limitations of the experimental environment, when the indoor air conditioning temperature was set to 16 \({}^{\circ}\)C, there was some deviation between the air conditioning display temperature and the actual indoor air temperature. The lowest room air temperature of 16.8 \({}^{\circ}\)C was recorded during the experiment, which may have affected the subjects' thermal perception. The detailed results are shown in Figure 6. Figure 6 shows that when the indoor air temperature was changed to a lower temperature of 16.8-20.1 \({}^{\circ}\)C, the subjects will produce cold uncomfortable body language such as 'rubbing hands', 'putting on a coat','stamp one's feet', etc. At different indoor temperatures, there were differences in the way multi-users express cold discomfort, that is, the type of body language expression was in dynamic change. Figure 6 shows that when the indoor temperature changes from 21.2 \({}^{\circ}\)C to 25.6 \({}^{\circ}\)C, the expression type of the subjects' body language is the same as that of the indoor temperature from 16.8 \({}^{\circ}\)C to 20.1 \({}^{\circ}\)C, but the number of subjects decreases gradually. At 25.6 \({}^{\circ}\)C, only three subjects had thermal discomfort body language; Figure 6 shows that when the indoor temperature changes from 25.9 \({}^{\circ}\)C to 27.1 \({}^{\circ}\)C, the type of body language expression of the subjects' changes, and the body language of 'rolled up sleeves' will be produced to express the feeling of thermal discomfort. With the increase in room temperature, the number of subjects with thermal discomfort body language expression increases. At 27.1 \({}^{\circ}\)C, four users produce thermal discomfort body language expression.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Thermal Comfort** & **Scale** \\ \hline Hot & +3 \\ Warm & +2 \\ Slightly warm & +1 \\ Natural & 0 \\ Slightly cool & \(-1\) \\ Cool & \(-2\) \\ Cold & \(-3\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: ASHRAE thermal comfort scale [32].  
Figure 6d shows that when the indoor temperature changes from 27.3 \({}^{\circ}\)C to 27.9 \({}^{\circ}\)C, the subjects gradually produce thermal discomfort body language such as 'wipe sweat', 'fan with hand', 'take off the coat', and other expressions of thermal discomfort. Figure 6e,f shows that when the indoor temperature is 28-30 \({}^{\circ}\)C, the number of subjects expressing thermal discomfort body language increases. When the indoor temperature is 30 \({}^{\circ}\)C, only two subjects do not do any thermal discomfort body movements. The results in the figure showed that multi-users in the same thermal environment will express discomfort through thermal discomfort body language, which proved that thermal discomfort body language can indeed represent personalized thermal comfort differences and proved the effectiveness of using it to predict thermal comfort.