Today, developments in wireless technologies and the increase in disaster cases reveal the necessity of various wireless technologies cooperation. Several technologies are able to cooperate with each other for eHealth, IoT, and so forth applications in disaster cases with the pros and cons of today's communications. Wireless Body Area Networks (WBAN) and cognitive radio (CR) are promising technologies that can be used together to troubleshoot communication problems and make rescue operations successful in disaster situations. WBAN is a radio frequency-based wireless network technology that aims to monitor the functions and conditions of the human body through the sensor nodes that form a network. CR proposes solutions to current problems of wireless communications such as spectrum scarcity and inefficient use of the spectrum. In this study, CR-based WBAN architecture is proposed in disaster cases, and so the emergency, time-critical, and vital signs of WBAN users (endangered people and rescue team members) are able to reach the health unit or disaster management unit in an opportunistic way. CR technology is integrated with a WBAN architecture utilizing the CSMA/C-based IEEE 802.15.6 standard, and performance analysis is executed with the Riverbed Modeler simulation software. Furthermore, using the channel bonding technique, the throughput, the delay, the packet delivery ratios, and energy consumption ratios of the proposed architecture are investigated. According to the results, it was found that CR-based WBAN architecture was 25% more successful in energy efficiency and 5% more successful in packet delivery ratio with channel bonding technique than the traditional WBAN. K E Y W O R D S channel bonding, cognitive radio network, disaster case, IEEE 802.15.6, wireless body area network 1 | INTRODUCTION Nature occasionally causes various problems such as tsunami, earthquake, hurricane, and flood. As a result, man and man-made structures are damaged. There were many earthquakes in the world in recent years especially in Turkey. The cellular communication infrastructure collapses for a long time immediately after the earthquake. The people