# Effect of Exposure Time on Thermal Behaviour: A Psychophysiological Approach
## 6 Conclusions  
The experiment collected data of five participants over the course of 6 weeks. The resulting datasets included climate, physiologic and behavioural data with varying resolution and finally matched time-wise. The analysis focused on the relationship between tonic EDA to understand the impact of the thermal stimuli on the human body in a varying spatiotemporal setup.  
Initial research question at hand was the correlation between time and thermal exposure. The data suggested that there was a difference in tonic EDA levels between \"morning\" and \"afternoon\" clusters although the environmental parameters were the same, suggesting a change in the human body's thermal reception over time. Even further, based on the person's chronotype, the beginning of the \"afternoon\" cluster was observed to have shifted according to the person's circadian rhythm. Such individual shifts have been remarked in the literature previously [77], and there are several studies that present data on the changes in the core temperature and on the skin conductance throughout the day [55, 56, 57, 58]. Understanding this phenomenon in the context of design and operation of the built environment might reveal opportunities in a change in office schedule-culture, which could mean lowering and balancing the energy demand throughout the day, while actually offering a healthier life-style for people as well.  
Second research question was whether taking cool breaks would help with such accumulation of stress in the body, and if so, whether a \"reset\" time could have been identified. However, the use of breaks as an adaptive behaviour did not take place as expected and the data did not yield clear trend. The authors intend to conduct further experiments to investigate this relationship again in the future, this time with controlled schedules.  
Finally, an underlying question was comparing health to comfort. As discussed previously, only focusing on one physiological output is not representative of the body'shealth panel but a mere scratch on the surface. However, initial comparisons reveal how the body reacts differently under the same PMV values, both within and between-subjects.  
At the moment no conclusion could be driven through the presented EDA data of any of the participants as to say what is \"healthy\" or \"not healthy\". This is for several reasons:  
1. As previously explained the absolute numbers do not reveal much and the evaluation should be done within-subject. Further longitudinal studies need to collect more data from individuals to identify trends of within-subject changes.  
2. While electrodermal activity was paralleled to a higher/lower sympathetic nervous system (SNS) activity, without cardiovascular activity a complete argument should not be made. The dermal related thermoregulation activities, as previously mentioned, employ vasomotor responses, which is directly connected to the blood flow. In order to dissipate more heat, the heart needs to direct a larger portion of blood circulation to skin, in some cases as much as 60% [78]. Management of these sudden peaks and blood pressure regulation is a health-critical SNS over-activity example. Therefore even though EDA levels are indicative of SNS load, cardiovascular data should be studied in parallel.  
3. Another important aspect is mental workload: with the blood redirection from organs to skin in order to achieve thermal homeostasis, cerebral blood flow is also impaired. Even a seemingly small rise of 0.3\({}^{\circ}\) K in core temperature (esophageal) with a rise of 3.8\({}^{\circ}\) K in skin temperature is found to cause a 15% decrease in blood flow in middle cerebral artillery flow [79]. While measuring the blood flow in brain systems may not be suitable in experiments designed in a climate chamber, the cognitive workload as a result of it may still be observed and measured via mobile EEG headsets.