Ruoyang Jin, Yong Liu, Heng Wu, Guangyu Zhang
Pendulum residents face compound heat exposure across day and night because their rigid commuting routines trap them in consistently hot environments. Traditional residence-based assessments often misestimate this risk, as they overlook the multidirectional nature of daily movements. This study addresses that gap by applying a job–housing mobility perspective that incorporates both home and workplace conditions, using Chongqing as the case study. Mobile phone signaling data were used to identify pendulum residents and map their multidirectional mobility patterns. Most of these residents are concentrated in the urban centers within the inner ring road, forming a tightly connected network of intra- and inter-cluster flows. In contrast, those living outside the inner ring road tend to have more localized, intra-cluster movements. We simulated hourly Mean Radiant Temperature (MRT) and calculated heat exposure by combining MRT with the duration of stay at each location. The results show that over 20% of pendulum residents experience compound exposure—high heat at work during the day and at home at night. Logit regression further reveals that short-range, intra-cluster mobility and movement within periphery areas are key drivers of compound exposure. Demographic factors such as being young or female, along with neighborhood characteristics like employment in industrial areas and limited public transportation access, also elevate the likelihood of experiencing this exposure. Together, constrained mobility and heightened vulnerability contribute substantially to the risk. The research framework is particularly applicable to large, polycentric cities with complex commuting patterns, where multidirectional mobility shapes uneven heat exposure across space and time. These findings highlight the need for targeted heat-mitigation strategies, such as improving mobility options, providing accessible cooling facilities, and protecting vulnerable groups.