## 4 Discussion  
### Clinically Acceptable Limits  
This study was undertaken to investigate the effectiveness of CT wearable sensors relative to the ICTS. The Bland-Altman plot indicated that SS read on average 0.20 \({}^{\circ}\)C higher than the ICTS, which is consistent with the data trend observed in Figure 3b which showed that the SS CT measurement was higher than the ICTS measurement. The hypothesis  
Figure 4: (a) A Bland–Altman plot and (b) CT data for the comparison of Zephyr and ICTS (n = 10 participants). testing (Wilcoxon test) determined that the mean difference (bias) was significantly different from zero. The Bland-Altman plot also showed a proportional bias indicating that the difference between SS and ICTS measurements was not consistent across the range of values. Therefore, adjusting the SS CT measurements by subtracting 0.20 \({}^{\circ}\)C (mean bias) might not necessarily make SS agree more closely with the ICTS because of the proportional bias. The proportional bias indicates that the bias in measurements varies systematically with the magnitude of the CT measurements. When proportional bias is observed, it becomes inappropriate to simply apply the mean bias (or fixed bias) to correct the measurements because it may lead to inaccurate adjustments, as the bias itself varies across different CT measurement levels. Therefore, alternative approaches should be considered to address the proportional bias. For instance, regression models or correction algorithms that consider the relationship between the measurements and the bias can be developed to make more accurate adjustments and improve the reliability of the CT measurements. In Table 4, when transitioning from mean to maximum CT, it was observed that the number of datapoints reduced from 80% to 50%, indicating that the SS device may have more variability in accurately tracking core body temperature during more intense physical activities. Additionally, the LoA showed that SS may measure 0.47 \({}^{\circ}\)C below and 0.88 \({}^{\circ}\)C above ICTS. Therefore, it may be necessary to calibrate or validate SS against ICTS or other reference devices before using them in applications that require very precise temperature monitoring. These results align with the outcome reported by [PERSON] et al. [19] that indicate that a SS wearable sensor is on average 0.03 \({}^{\circ}\)C higher than ICTS with standard deviation of 0.3 \({}^{\circ}\)C. However, the different bias, RSME, and MAE values reported in this study and the study conducted [PERSON] et al. could be due to different versions of SS devices being explored. The present study used the BAND V1 while [PERSON] et al. investigated BAND V2. The bias, RSME, and MAE value were also lower in the outcome reported by [PERSON] et al. relative to the outcome of this study, indicating that SS has improved on their BAND V2 wearable sensor. Based on the available evidence, it appears that SS has shown to be reliable and accurate in measuring individuals' CT. When exploring the efficacy of the Zephyr CT wearable sensor, the Bland-Altman plot showed that Zephyr read on average 0.03 \({}^{\circ}\)C less than ICTS, which is also evident in Figure 4b. However, the Bland-Altman Plot and linear regression showed that there is proportional bias; therefore, the mean bias (\(-\)0.03 \({}^{\circ}\)C) can not simply be applied to correct the CT measurements because the bias itself varies across different CT measurement levels. Therefore, regression models or correction algorithms that consider the relationship between the measurements and the bias can be developed to improve the reliability of the CT measurements. Furthermore, the LoA indicated that Zephyr may measure 0.67 \({}^{\circ}\)C below and 0.62 \({}^{\circ}\)C above the ICTS. Therefore, in situations where very accurate CT is required, it is important to consider the potential for measurement error and take additional measures such as multiple readings.