Global climate change and intensifying heat islands have reduced human thermal comfort and health in urban outdoor environments. However, there has been little research that has focused on how microclimates affect human thermal comfort, both psychologically and physiologically. We investigated the effect of a range of landscape microclimates on human thermal comfort and health using questionnaires and physiological measurements, including skin temperature, skin conductance, and heart rate variability, and compared the results with the effect of prevailing climate conditions in open spaces. We observed that in landscape microclimates, thermal sensation votes significantly decreased from 1.18 ± 0.66 (warm–hot) to 0.23 ± 0.61 (neutral–slightly warm), and thermal comfort increased from 1.18 ± 0.66 (uncomfortable–neutral) to 0.23 ± 0.61 (neutral–comfortable). In the landscape microclimates, skin temperature and skin conductance decreased 0.3 ± 0.8 °C and 0.6 ± 1.0 μs, respectively, while in the control, these two parameters increased by 0.5 ± 0.9 °C and 0.2 ± 0.7 μs, respectively. Further, in landscape microclimates, subject heart rate variability increased significantly. These results suggest landscape microclimates improve human thermal comfort and health, both psychologically and physiologically. These findings can provide an evidence base that will assist urban planners in designing urban environments for the health and wellbeing of residents.

The global spread of COVID-19 has disrupted the normality of people’s daily lives, leading the population to social distancing and isolation. The closure of green areas also affected the well-being of the individual during the COVID-19 pandemic. Viewing flowers is expected to have similar positive effects to viewing natural scenery. Therefore, this study investigates how white, red, and yellow flower colors affect individuals’ psychological and physiological well-being. The experiment was conducted in an office-like setting with 50 participants. Participants looked at each flower color for 3 min. Electroencephalograms (EEGs), heart rate variability, and skin conductivity were measured to evaluate physiological responses along with both the semantic differential questionnaire (SD) and the Profile of Mood States (POMS) to assess psychological responses. EEGs showed that the mean values of alpha relative power in the prefrontal lobe were significantly higher when viewing yellow and red flowers vs. white flowers. Furthermore, heart rate variability revealed that viewing yellow and red flowers increased parasympathetic nerve activity significantly. After viewing the yellow and red flowers, the average results for each subscale of the POMS questionnaire improved. The vigor (V) subscale and overall mood status values were significantly improved. The results of the SD method revealed that viewing yellow and red flowers resulted in a significantly higher sense of relaxation, cheerfulness, and comfort than viewing white flowers.

In recent years, children’s use of mobile phones has grown rapidly, which might lead to an increase in mental stress and negatively affect their health. Despite increasing evidence that horticultural activity can provide significant health benefits, few scientific evidence-based studies are currently available regarding these benefits to children’s health and wellbeing in schools. Therefore, this study aims to determine the potential benefits of horticultural activity for children from both psychological and physiological perspectives. Twenty-six elementary school students (mean age, 8.12 ± 0.21 years) were asked to perform a plant-related task and a mobile game task for 5 min. During both tasks, physiological sensors were used to measure the participants’ heart rate variability, skin conductance, and skin temperature. Additionally, the participants’ emotional responses were assessed using semantic differential and State–Trait Anxiety Inventory tests immediately after each task. Results revealed that, compared with the mobile game task, participants’ health statuses were positively correlated with the horticultural task, including a considerable decrease in skin conductance and sympathetic nervous activity, together with a marginal increase in parasympathetic nervous activity. Such responses suggested that horticultural activity increased relaxation and decreased feelings of stress. Furthermore, the horticultural activity was associated with a substantial increment in comfort, naturalness, relaxation, and cheerfulness feelings, as well as a significant reduction in depression and a reduction in total anxiety levels. Given these positive benefits, horticultural activity may provide a great contribution to children’s healthy life at school, prompt psychological relaxation and minimize mental stress relative to smartphone games.

The therapeutic advantages of seeing plants have gained increasing consideration in stressful modern societies, however, evidence-based studies on how physiological and emotional states of individuals from different nationalities change when seeing different foliage colors are limited. The study was conducted to explore the physiological and psychological advantages of foliage colors as visual stimuli. The experiment included 40 men from two nations (age: 21.34 ± 3.50 years) and was carried out using five foliage colors including green, light green, green-yellow, green-red and green-white. Participants were exposed to each color for 2 min, when seeing the foliage colors, eye movements and oxy-Hb concentrations were continuously measured. Subjective evaluations of emotions were performed utilizing a semantic differential questionnaire. A significant decrease in oxy-Hb concentration in the frontal lobe was associated with the viewing of green and green-white plants by the Japanese participants and with viewing light green and green-yellow by the Egyptian participants. Participants spent higher fixation numbers and longer durations on these colors. The findings indicate that viewing of these plant colors was positively associated with physiological relaxation. Furthermore, these colors were associated with more positive feelings, such as calmness, comfort and naturalness. Therefore, the presence of these colors in spaces may have positive impacts on relaxation and emotional status.

The locality of landscape design needs to obtain human thermal perception in different cities or regions. Previous studies in Shanghai have focused on a single season and ignored the seasonal characteristics of hot summers and cold winters. The objective of this research was to examine the outdoor human thermal perception in three seasons—summer, autumn, and winter. For this purpose, a field survey was conducted in two urban squares in Shanghai, and during three seasons, an outdoor human thermal perception questionnaire survey was completed combined with micrometeorological measurements. In the questionnaire, the thermal sensation and thermal comfort of interviewees were evaluated through the 9-point scale and the 4-point break scale, respectively. Regression lines gave the possibility to calculate the neutral ranges and the comfort ranges. A neutral PET (physiological equivalent temperature) range of 13.0~28.6 °C and a comfort PET range of 14.2~32.6 °C were obtained for three seasons. In addition, the relationships between personal (gender and age of respondents) and microclimatic (air temperature, relative humidity, wind velocity, and solar radiation) factors on thermal sensation votes (TSV) and thermal comfort votes (TCV) were evaluated. The results of multiple regression analysis showed that the variables affecting TSV and TCV changed with the season. The findings of this research enhance our understanding of outdoor human thermal perception and can contribute to more friendly outdoor open space design in Shanghai.

Outdoor public spaces that provide a comfortable microclimate significantly contribute to urban livability. However, more elaborate investigations are needed to enhance the research-based design of landscape spatial form for optimal thermal comfort performance. This study aimed to optimize the morphological design of urban squares considering summer and winter microclimates by integrating multiple landscape elements of vegetation, waterbodies, buildings, and ground. The built environment microclimate simulation and validation of multi-physics coupling were conducted for thermal comfort, planar heterogeneity diagramming, and spatial typology identification. Further, research through design (RtD) was applied to reconstruct various spatial configurations and orientation forms to compare the relative thermal comfort areas of these geometrical prototypes in the target time period and square core zone. Among the landscape types, two identified spatial types for achieving better thermal comfort are the opening of a windward enclosure structure (ECS) that draws wind into the square in summer and an ECS without a windward opening that creates a more extended wind protection area in winter. Moreover, results of RtD show that the prototype with the smallest orientation angle to the prevailing wind direction has the most optimized thermal comfort during summer, while the form with a smaller angle to the prevailing wind direction is more favorable in winter. These findings provide methodological guidance for climate-adapted landscape square form optimization.