This article proposes a novel cost-effective, robust, reliable and flexible infrastructureless IoT multi-hop Wireless Mesh Network (IoT-WMN) for Public Safety and Disaster Response (PSDR). The proposed system is able to auto-detect an Emergency Relief State (ERS) due to a disaster and to auto-configure itself in order to remain up and running, regardless of the disaster nature, to help victims to be timely rescued. To achieve this goal, these networks must be installed quickly and transparently for users, as victims cannot be expected to perform configuration operations or certain multi-hop-enabled software installed on their devices. in case of ERS detection, the system sets up ad hoc connections self-organizing links according to a tandem-based WMN topology and self-configuring access points (APs) for wireless devices (e.g., mobile phones of disaster victims). Devices connected to ad hoc APs become APs in …