Thermal pleasure–based spacing of mist–shade umbrellas in hot–humid outdoor walkways using an extended JOS-3 model

Studies on pedestrian thermal pleasure (TP) in summer have mainly focused on the instantaneous cooling effects of microclimate-regulation facilities. However, to enable rational planning of microclimate-regulation facilities, the dynamics of TP during the post-cooling walking process remains insufficiently understood. This study conducted field experiments along a landscape walkway in Guangzhou, China, to examine how mist–shade umbrella (MsU) affect the induction and dissipation of TP under hot–humid subtropical conditions. The results showed that MsU exposure significantly improved the pedestrian-level thermal environment, reducing UTCI by 6.1 °C relative to the sun-exposed section and by 1.2 °C relative to the tree-shaded section. Regardless of prior thermal exposure, entering the MsU induced TP with comparable intensity. However, after leaving MsU, TP dissipation was strongly governed by subsequent thermal exposure, decaying rapidly under sun exposure (−35%) but much more slowly under tree-shaded conditions (−3%). Further analysis indicate that both instantaneous TP and its cumulative dissipation are significantly associated with upper-body skin temperatures and accumulated heat load of the body. Using the back-skin-temperature threshold (34.9 °C) and an extended JOS-3 simulation, TP was sustained for 28 min under the shade-recovery conditions (UTCI = 38.5 °C), implying a cooling-point spacing of 1.4 km, providing quantitative evidence for planning of MsU along hot–humid landscape walkways.