## 4 Discussion
### Relationship between Wearable Sensors and ICTS  
The correlation coefficient of 0.543 suggests that there is a moderate positive relationship between SS and ICTS. This is similar to the correlation coefficient 0.595 reported by [PERSON] et al. [19]. This means that as the temperature recorded by ICTS increases, the temperature recorded by the SS tends to increase as well. The significant \(p\)-value of less than 0.001 indicates that the correlation is not due to chance, and the large sample size of 421 further strengthens the statistical power of the analysis. Overall, the results suggest that ICTS and SS may be comparable and interchangeable for certain applications, but caution should still be exercised when interpreting the results. For example, if ICTS and SS are being used in a medical setting where precise temperature measurements are critical, the correlation coefficient may not be high enough to justify using the ICTS and SS interchangeably.  
For Zephyr, a moderately positive association was observed between Zephyr and ICTS, and hypothesis testing indicated that there is agreement between both devices indicating that Zephyr may be a reliable alternative to ICTS. This is because as the temperature recorded by the ICTS increases, so does the temperature recorded by Zephyr. However, the correlation coefficient of 0.524 suggests that there is still a significant amount of variation between the measurements of the two devices. This means that there may be other factors that are influencing the measurements, such as differences in calibration or placement of the devices. The significant \(p\)-value of less than 0.001 indicates that the correlation is not due to chance, and the sample size of 421 further strengthens the statistical power of the analysis. This result aligns with the findings of past studies that evaluated the relationship between Zephyr and a gold standard and reported moderate positive association (correlation coefficient = 0.643 [34]) and moderate-strong association (correlation coefficient range from 0.679 to 0.858 [23]). The correlation coefficient recorded in this study (\(\rho\) = 0.524) was lower than that recorded in other studies probably because of the differences in the kind of participants, activities, environments [23; 34], or gold standards [23] that were used. Furthermore, [PERSON] et al. [38] explored Zephyr efficacy in severe heat stress. The study found that out of 499 individuals identified as potential cases of exertional heat stroke, only 10 were confirmed to have the condition. These findings indicate that Zephyr has a significant number of false positive and false negative results when used in this particular situation [38]. Overall, these findings suggest that while the Zephyr and ICTS may be comparable, they cannot be used interchangeably without caution.  
Further research may be needed to explore the reasons for the differences between the devices and the ICTS and to determine the extent to which they can be substituted in practice. Factors such as calibration, placement of the devices, and other environmental variables may also affect the measurements and should be taken into consideration. Additional research may be needed to further explore the reliability and validity of the devices being compared, especially regarding variable workload as it can be found in a typical occupational setting [23].