## 4 Discussion
### Individual Differences  
Despite controlling the hot environment, standardized outfit, and exercise protocol, individuals displayed diverse responses to the different sensors used and the CT measurement. This prompted the analysis of participants' individual differences, such as their past experience exercising in hot conditions, workout intensity, and BMI. The result revealed that there was no statistically significant impact on the CT measurement when using the SS device. However, despite the lack of statistical significance, noteworthy observations were made. Firstly, participants who never avoided exercising in hot conditions exhibited the highest CT compared to those who sometimes avoided exercising in hot conditions. This finding suggests that individuals with a history of exercising in hot environments may have developed heat acclimatization, allowing their bodies to adapt and regulate temperature more effectively [39]. Secondly, when examining the influence of exercise intensity on CT, participants engaging in moderate-intensity exercise displayed the highest CT, followed by those performing low-intensity exercise, and finally, participants engaging in vigorous-intensity exercise exhibited the lowest CT. This pattern could be attributed to the increased muscular activity and energy expenditure associated with moderate-intensity exercise, leading to greater heat production [39; 40]. Furthermore, participants performing moderate-intensity exercise likely sustained the dumbbell curling task for a longer duration, resulting in prolonged exposure to the generated heat from both muscular activity and the surrounding environment. Previous studies have demonstrated that during moderate-high intensity exercise, the body generates heat at a faster rate due to elevated metabolic activity, leading to a notable rise in CT [40; 41; 42]. Lastly, participants who were overweight exhibited the highest CT measurements, while underweight participants had the lowest CT. This observation aligns with previous research indicating that individuals with higher body mass tend to have a higher metabolic rate, resulting in increased heat production [43; 44; 45]. Additionally, adipose tissue, which is more prevalent in overweight individuals, acts as insulation and impedes the dissipation of heat from the body to the environment [43]. There is a need to investigate other factors such as hydration status, fitness level, acclimatization, resting metabolism rate, among others that have the potential to statistically significantly influence SS CT measurement and cause large individual variability. Similar factors were considered when investigating participants' individual differences that could affect CT measurement using the Zephyr device. It was found that past experience exercising in hot conditions and the intensity of workouts had a significant impact on Zephyr CT measurements, while BMI did not show a significant effect. Specifically, participants who never avoided exercising in hot conditions recorded significantly higher CT than those who sometimes avoided exercising in such conditions. This suggests that individuals with a history of exercising in hot environments exhibit distinct CT responses, possibly due to enhanced heat acclimatization and improved thermoregulation capabilities. Additionally, participants engaging in moderate-intensity exercise exhibited the highest CT, followed by those involved in low-intensity exercise, while participants performing vigorous-intensity exercise recorded the lowest CT. This finding suggests that the level of exercise intensity impacts Zephyr CT measurement dynamics, with greater muscular activity and energy expenditure contributing to elevated CT levels (CITE2). Regarding BMI, although we did not find a significant effect on Zephyr CT measurements, it is worth noting that overweight participants recorded the lowest CT measurements compared to underweight and healthy weight participants.