## 1 Introduction
These challenges are particularly pronounced in urban, rural, and coastal settings, with each presenting unique obstacles and requirements for effective safety monitoring. Comprehensive solutions are needed to address the complexities of outdoor safety monitoring in different environments [19]. New applications and tools enable interdisciplinary approaches while addressing ethical and social implications. Integrating humans, technology, and the environment is crucial to measuring and improving safety, biohealth, and climate resilience. By focusing on these three dimensions, it is possible to develop not only technologically advanced but also socially responsible and environmentally sustainable systems. The successful development of a comprehensive solution will bring many benefits to society. Not only will it reduce accidents and improve emergency response through real-time monitoring and predictive analytics, but also the ability to monitor biohealth indicators will prevent health crises and promote healthy behaviors. Human activity recognition (HAR) focuses on identifying and analyzing human actions through sensor data [20]. Integrating HAR with IoPVT in the Metaverse allows systems to collect data in real time, create virtual replicas of physical environments, and allow for timely interventions and informed decision making to prevent accidents and emergencies [21]. This integration promises to revolutionize safety monitoring by providing a comprehensive, interactive, and predictive approach that adapts to the specific needs of different environments. This paper aims to explore and articulate a future in which outdoor safety monitoring is significantly enhanced through the integration of HAR with IoPVT in the Metaverse. The proposed system addresses various challenges and illustrates the versatility of the physical-virtual intertwined approach. We focus on the interaction between humans, technology, and the environment to create a holistic monitoring system that leverages edge-based sensor data fusion, fog computing, and cloud analytics to enable real-time data processing and decision-making [22]. By presenting a cohesive vision, the paper aims to contribute to the advancement of outdoor safety monitoring technologies and establish a roadmap for future research and development efforts. Specifically, this paper will make the following contributions:  
* _Present a Conceptual HARISM Framework_: This vision paper outlines a framework for HAR with IoPVT for safety monitoring (HARISM), which focuses on outdoor safety applications, integrating HAR with IoPVT and Metaverse to proactively safeguard public spaces across different environments. * _Explore Technological Innovations_: A thorough discussion is presented on the advancements in sensor technologies, AI-driven HAR techniques, and computing architectures like edge, fog, and cloud computing. Figure 1: Comparison of traditional IoT vs. IoPVT systems. * _Examine Societal Benefits_: The paper highlights the potential for proactive health monitoring, enhanced emergency response, and contributions to smart city and community initiatives. * _Address Challenges and Research Directions_: This paper identifies technical, ethical, and policy-related challenges, emphasizing the need for interdisciplinary collaboration. The remainder of this paper is structured as follows. Section 2 gives an overview of the conceptual framework and the enabling technologies for outdoor monitoring systems enabled with the IoPVT. Section 3 thoroughly discusses HAR, the core technology of the envisioned paradigm. Section 4 emphasizes the social benefits and impacts. Section 5 illustrates the applications in urban, rural, and coastal cities as case studies. Section 6 indicates the challenges and opportunities and highlights critical research directions in the near future. Finally, Section 7 concludes the paper with some final thoughts.